documentpe

2007

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Production Engineering Department

Shantilal Shah Engineering College

Plant engineering

PRODUCTION ENGINEERING DEPT. s.s.e.c. Bhavnagar 2

CERTIFICATE

This is to certify that Mr./Miss

_______________________________________________________________

Student of semester - VIII Production

Engineering,Roll No. _______ of S.S.Engineering College has

Satisfactorily accomplished his/her term work by

submitting this file of ______________________________________

on Date: ___________

Examinor Head of the Dept

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INDEX

Sr.

No.

Name of Experiment Page

From To

Date of

Start

Date of

Complet

-ion

Sign

1. Write-up on selection of plant

location

2. Write-up on plant location,

layout & line balancing

3. To study of computerized

layout planning

4. To study of flow pattern for

material in production line &

case study on line balancing

5. Write-up on group technology

and process planning

6. Write-up on flexible

manufacturing system

7. To study about line of balance

8. Write-up on material handling

9. Write-up on material handling

equipment

10. To study about safety

engineering

11. To study about plant

maintenance

12. Write-up & case study on

TPM

13. To study about activity

relationship chart & activity

relationship diagram

14. To study about different

models for selection of

location

15. Write-up on different types of

industrial acts

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EXPERIMENT.NO: 1

AIM: - WRITE-UP ON SELECTION OF PLANT LOCATION

INTRODUCTION:-

- When it has been decided to start a factory, it is most important to select the suitable site

or location to house the factory.

- The location has the great effect on the success or failure for the operation of the plant.

Therefore, it should be based upon the careful consideration of all factors that are

essentially needed in efficient running of the particular industry.

- The necessary factors in the selection of the plant location vary among industries and

with changing technical and economical conditions.

- Some industries tended to follow their markets in the locations of their plants such as

plastic industries, textile industries of Bombay, and nangal fertilizer near bhakhra dam

and chitranjan locomotives near maithan dam are located around the source of power.

STAGES OF SELECTION OF THE SITE:-

THE GENERAL LOCATION OF THE FACTORY:-

Following factors must consider in this respect.

1. AVAILABILITY OF THE RAW MATERIAL:-

1. As far as possible the site selected should be near the source of the raw material so that

the cost of the transporting of the raw material to site may by minimum.

2. Further if the raw materials are bulky it becomes very essential to select the site near it.

3. If the raw materials are perishable, as sugarcane, proximity to supply of raw material is

an advantage.

2. PROXIMITY TO MARKET:-

1. The cost of transporting finished goods, advertising and distribution etc. will be greatly

reduced if the factory is situated near the market. So the goods can be sold at cheaper

rates.

2. Secondly it will help in quick service to the customers and their requirements can also

be studied quickly and easily.

3. TRANSPORT FACILITIES:-

1. Transportation costs of raw material plays an important role, specially when the raw

materials are bulky and of low value. Therefore, most of the iron, coal and other heavy

chemical industries are located at the raw material centre.

2. Similarly when finished product is heavy, nearness to the market is economical.

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3. Now, with the development of diesel trucks road transport has become a successful

competitor of rail transport on account of the advantage of quickness and convenience

of door-to-door service and lead to the location of some of the new factories on the

road side.

4. AVAILABILITY OF EFFICIENT AND CHEAP LABOUR:-

1. While selecting a site, it is necessary to consider that whether right kind of labour at

suitable rates is available or not, because labour cost is an important item of the total

production cost in mfg.

2. The famous glass and bangle industries at Firozabad, that of woolen carpets at

Mirzapur and silk sarees at Kanjivaram etc. is mainly due to the high skilled labour for

that particular industry available at these places.

5. AVAILABILITY OF POWER AND FUEL:-

- In the last century, the industries were situated near coalmines or places to which coal

could be carried easily and cheaply. But due to development of high-tension grid

system this factor is not of much importance now.

6. CLIMATIC AND ATMOSPHERIC CONDITIONS:-

- It is governing factor for several industries, as cotton industries required moist climate

that is why, most of the textile mills have been located at Bombay and a‟ bad. But now

days with the development of air-conditioning process, it has been possible to control

the atmospheric moisture contents in the factory according to the requirements.

7. AVAILABILITY OF WATER:-

- All factories need soft and pure water; hence its search should be made whether good

quality of water is available or not. If not available, then its cost of transport has to be

given prime consideration.

8. AVAILABILITY OF CAPITAL:-

- The supply of capital is an important factor on the rate of development of a factory.

Amount of capital available helps in determining the size of the plant and its future

plans.

9. SOCIAL AND RECREATIONAL FACILITIES:-

1. Usually big factories are located away from the public, social and recreational centers.

2. During off hours, the employees require some social and recreational amenities, which

are the necessities of the life. Therefore, it is essential that the employer or government

near factory site should provide suitable parts, co-operative stores cinemas and

educational centers, if these are located away from the local towns or cities.

3. These amenities will keep the worker healthy; build good habits and workers,

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therefore, will take much interest in work.

10. BUSINESS COMMERCIAL FACILITIES:-

- Availability of the financial and banking facilities is an important consideration for the

factories, which require constant feeding of the working capital.

11. EXISTENCE OF RELATED INDUSTRIES:-

1. In the case of small scale industries repairing is a problem.

2. If such a facilities are available in the existing areas, repairs are carried out

immediately without affecting the production.

12. OTHER FACTORS:-

- The factors like local byelaws, taxes, fire protection facilities, post and telegraph

facilities should also be considered.

SELECTION OF ACTUAL SITE:-

The most important factors in this respect are:

1. Availability of cheap land to build and expand the plant.

2. The cost of leveling the land and providing foundations, sub soil conditions for

foundations and drainage.

3. The cost of bricks, send, cement, lime, steel, and other materials required for

construction.

4. Facilities for the upkeep and general maintenance.

5. Facilities for transport in getting and sending materials.

6. Facilities for the housing the workers and if necessary, their transport from their places

of residence to the work sites.

7. Cost of laying the water supply and providing sewage and disposal work.

8. Cost of installation of electricity, gas and other facilities etc.

9. Cheap possibilities for disposing of trade waste.

10. Any restrictions placed by the town planning department or local bye-laws be well

studied.

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DETERMINATION OF MOST ECONOMIC SITE OR LOCATION:-

[Figure 1.1: Determination of most economic site or location]

- Let R1 and R2 be the two available sources of raw material supply and one place of

market or consumption is N.

- Suppose L is the location of the factory. Then if L is at M, only freight on the raw

material will be paid or if L is at R1 or R2, there will be distribution charges on the

manufactured goods.

- Now, again if an intermediate place is selected both incoming and outgoing freights will

be paid.

- Actually in practice a comparison should be made of each element of the total cost

required to be involved, if the plant was erected at the each of these alternatives.

A CASE STUDY OF THE SATURN AUTOMOBILE:-

SITE SELECTION:-

1. THE PROCESS:-

GM announced their plan for a site search for the new Saturn Facility January 9,

1985. 22 Previous GM plant locations had always been conducted behind closed doors. 23

In the case of this site selection the process was done in public. It started as a bidding war

between politicians and business men intent on landing 6000 jobs and the $5 billion project

in their state. ~ Illinois offered financial assistance, cheap real estate and even tax breaks as

incentives. 25 There was an organized letter writing campaign organized in Iowa where

school kids sent letters to GM asking for consideration. 26 Governors of several states even

resorted to the '92 presidential campaign tactic of appearing on TV talk shows to advertise

their package to GM. N Another tactic used was the purchase of billboard advertisements in

Detroit. This was intended to draw attention to certain areas for consideration. 28 Tennessee

played the game low key. They didn't send politicians to Detroit or buy billboard space. 29

During the bidding war GM claimed that this was not what they wanted. Not everyone

believed GM. GM even attempted to downplay the importance of economic aid. Roger

Smith publicly stated that GM was interested in community stability and quality schools for

their employee‟s more than economic aid. 3° it is interesting to note that Japanese car

R1

L

R2

M

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companies building plants in the U.S. have used the public bidding technique to their

advantage in the past. 31 Honda, Mazda and Nissan all received generous economic

packages for their site selections,

2. SITE SELECTION ANNOUNCEM~TT:-

Finally in August 1985, several months behind schedule, GM announced Spring

Hill, Tennessee as the winner of the contest. 33 Those who had so vigorously pursued

Saturn missed the mark. GM used factors across the spectrum to make their final decision

rather than limiting the selection to the more tangible economic benefits. Saturn

Corporation released it's rationale for the Spring Hill decision. The list revealed the way

Saturn intended to conduct its business in the future.

3. REASON FOR SPRING HILL SELECTION:-

After the site selection announcement, Tennessee Governor Lamar Alexander

stated, "this is a national verdict establishing Tennessee as the best environment in America

in which to build the highest quality cars at the lowest price. ''~ In a document obtained

from Saturn Corporation the reasons for selecting Spring Hill are listed. The following is a

synopsis of that document.

4. AVAILABLE LAND:-

Purchased 2450 acres of land for the plant facilities. CENTRAL LOCATION

Spring Hill is within 600 miles of 65% of the nation's population.

5. FAVORABLE BUSINESS CLIMATE:-

Middle Tennessee was interested in expanding their industrial base. They were

willing to provide tax incentives and help with building infrastructure. Tennessee provided

$30 million for a 4-1ane access parkway to I65. The state also provided $22 million for

training programs for Saturn people. Maury County gave a 40-year in-lieu-of-tax agreement

to provide funds for community growth. This was a two way street-- Saturn paid $1.25

million for a new Spring Hill city hall and donated 50 acres of property for a new high

school.

6. AVAILABLE SERVICES:-

Good schools and medical care nearby. General services such as shopping malls on

hand.

7. VARIETY OF LIFESTYLES:-

City living (nearby Nashville) and a rural lifestyle available. PHYSICAL

CONDITIONS Good climate for materials shipment and comfortable for employees.

Topography was advantageous for plant construction. Rolling terrain allowed Saturn to hide

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facility from main highway and live up to promises made to the community not to disturb

the rural aesthetics of the area.

8. LOCAL PERSPECTIVE:-

All was not roses with the selection of Spring Hill. Not all who lived in the area

supported GM's decision to locate Saturn Corporation in Middle Tennessee. Two main

issues surfaced as a result of Saturn's new plant. The first problem surfaced as a result of

Saturn's hiring practices. Even though Saturn had publicly said they would hire many from

the local population in reality hired mostly imported workers from GM. 36 They imported

3300 for the first 4000 jobs at Saturn. 37 This practice caused resentment by the local

population. Additionally the schools became overcrowded with Saturn kids. 3g Saturn

worked hard to defuse the tension by building a new city hall and donating 50 acres of land

for a new high school. 39

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EXPERIMENT.NO: 2

AIM: - WRITE-UP ON PLANT LOCATION LAYOUT AND LINE BALANCING

DEFINITION OF PLANT LAYOUT:-

It is the arrangement of machines within a factory, so that each operation is

performed at the point of greatest convenience.

Plant layout may also be defined as “a technique of locating different machines and

plant services within the factory so that the greatest possible output of high quality at the

lowest possible total cost be available.”

Proper plant layout is one of the keys of success of in factory management. It

signifies arrangement of machines, work area, transport, storing of materials and processing

of different parts.

The layout for the same product may be numerous but which costs least to process is

the best. These vary with size and type of plant.

MAIN OBJECTIVES OF SCIENTIFIC LAYOUT:-

These are:

1. To produce better quality of products.

2. Maximum utilization of floor area.

3. Lower cost of scrap and waste.

4. Fewer accidents.

5. Space for future expansion.

6. Easy supervision.

7. Savings of cost.

8. Neatness.

9. Safety of equipment and personnel.

PRINCIPLES OF PLANT LAYOUT:-

According to Murther, there are six basic principles of “best layout”.

These are:

1. PRINCIPLE OF OVER-ALL INTEGRATION:-

According to this principle, the best layout is one which integrates the man,

materials, machinery, supporting activities and any other such factors that result in the best

compromise.

2. PRINCIPLE OF MINIMUM DISTANCE:-

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According to this principle, other things being equal, the best layout is one in which

men and materials have to move the minimum distance between operations.

3. PRINCIPLE OF FLOW:-


arranges the work area for each operation or process in the same order or sequence that

forms treats or assembles the materials.

4. PRINCIPLE OF CUBIC SPACE:-

According to this, the best layout is one in which all the available space both

vertical and horizontal is most economically and effectively used.

5. PRINCIPLE OF SATISFACTION AND SAFETY:-


makes work satisfying, pleasant and safer for workers.

6. PRINCIPLE OF FLEXIBILITY:-


can be adopted and re-arranged at a minimum cost with least inconvenience.

FACTORS AFFECTING THE LAYOUT:-

These are:

1. TYPE OF INDUSTRY:-

Industries are generally classified according to their process of manufacture. The

process of manufacture can be classified into four categories:

SYNTHETIC PROCESS:-

When two or more materials are mixed to get a product, the process is known as

synthetic process. The example of such a process is to produce the cement by mixing

limestone and clay.

ANALYTIC PROCESS:-

This is opposite of synthetic process. It is the breaking up of a material into several

parts. The refining of the petroleum is the example of this case.

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CONDITIONING PROCESS:-

In the conditioning process, the form of raw material is changed into desired product

as is jute industry.

EXTRACTIVE PROCESS:-

In this type, by applying heat, desired product is extracted from the original raw

material e.g. manufacture of Aluminium from Bauxite.

2. TYPE OF PRODUCTS:-

Type of product means whether the product is heavy or light, large or small, liquid

or solid. It is also a consideration in plant layout.

3. VOLUME OF PRODUCTION:-

According to this point, while plant layout is being one, it should be kept in mind

that, what volume is required to be produced. In this case, it should be seen that whether

Job production, Batch production or Mass production is being adopted.

4. INFLUENCE OF PROCESSES:-

Last factor, in which the process through which the material passes in the concern.

Much care should be given to the material handling problem, position of the store room and

tool room.

METHODS OF LAYOUT:-

Keeping in view the volume of production, and type of industry there can be

following methods of layout.

1. Line or product layout

2. Functional or process layout

3. Fixed position layout

4. Combination

1. LINE OR PRODUCT LAYOUT:-

This layout is very popular in mass production. In this layout only one product or

one type of product is produced in the operating area. To justify the layout, the product

must be standardized and manufactured in huge quantities.

Suppose the factory manufactures taps, drills, reamers and cutters. So there are four

separate departments to produce the articles. The machines are arranged according to the

sequence of operation. For example, in the reamer department, there will be the group of

the

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[Figure 2.1: Product lay out]

lathe to turn the reamer blanks, then workpiece goes on the heat treatment department for

the finishing purposes. This type of layout is shown in fig.

SUITABILITY:-

It is suitable for continuous process industries such as cement mfg., car or automobile

industries, chemical industries etc.

ADVANTAGES:-

1. Overall mfg time is low.

2. Less space is required.

3. Handling and transportation is minimum.

4. Better utilization of machines and labour.

5. Smooth flow of materials.

DISADVANTAGES:-

1. Requires changes because when the model or type changes, layout of machinery also

require changes.

2. Great machine idleness.

3. Not possible to add more machines.

4. Worker is not skilled for other machines or operations.

5. Specialized and strict supervision is required.

2. FUNCTIONAL OR PROCESS LAYOT (GROUP TECHNOLOGY):-

In this layout the machines are arranged on the functional taps, drills, reamers and

cutters may be the four department like lathe, milling, heat treatment and grinding, each

responsible for specific operations. All the products manufactured in this factory have to

pass through this four principle operations.

G

HT M

L M L

Entrance of materials

Finished product

G

Finished product

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Fig. Shows this arrangement.

[Figure 2.2: Process lay out]

SUITABILITY:-

It is very suitable where low volume of production is required. In this layout, similar

equipments and similar machines are grouped together that‟s why it is called Group

Technology.

ADVANTAGES:-

1. Supervision is simple because similar jobs are manufactured on similar machines.

2. Less machines are require.

3. The layout is flexible because it can be easily managed to change in the design of the

product, rate of production, methods of the production or the raw materials used.

4. Any breakdown of machine does not effect the production because it can be done on

standby machines.

DISADVANTAGES:-

G G

HT HT

M M M M

L L L L

Finished product

Grinding department

Heat treatment

Milling department

Lathe department Raw m/t entrance

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1. Production control more difficult and more costly because it makes necessary to plan and

supervise the work of each department each worker and machines. 2. More floor area is required.

3. Total production cycle time is more because long distance and waiting.

4. Routing and scheduling is more difficult because the work does not flow through the

definite mechanical channels.

3. FIXED POSITION LAYOUT:-

[Figure 2.3: Fixed position lay out]

This layout is used in manufacturing huge aircrafts, ship vessels, and pressure

vessels etc. where the product materials are too heavy. For such type of products, it is

convenient and economical to bring the tools, machines, worker to the work places. This

type of layout was very common before the Industrial Revolution but now-a-days it is easy

and more economical to move the material to the equipment and materials. Fig. Shows this

layout.

ADVANTAGES:-

1. Capital investment is minimum.

2. Continuity operations are ensured.

3. Less total production cost.

4. Less material movement.

DISADVANTAGES:-

1. Machines and tools etc. take more time to reach to the work place.

2. Highly skilled worker are required.

3. Complicated jigs and fixtures may be required in fixing jobs, tools etc.

4. COMBINATION:-

Components

Raw material

Machine

Tool

Workers

Assembled product from several components

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Now-a-days any one form of the layout in pure state is rarely used. Therefore, the

combinations of two or three layouts are used according to the requirement of industry. In

factory, production are first manufactured then assembled, this method is mostly used.

LINE BALANCING:-

Line balancing in a layout means balancing the production line or an assembly line.

The problem of line balancing is particularly important in product layout. It may arise due

to the following factors:

1. The finished product is the result of many sequential operations.

2. The production capacity of each machine in the sequence is not identical.

Suppose, there are three machines (workstations) A, B and C which can process 25,

50 and 100 pieces per hour respectively and the pieces flow from A to B to C (precedence

constraint). Since, A has minimum capacity, i.e. of processing 25 pieces per hour, work

statition or machine B will remain idle for 50% of its time and machine C will also remain

idle for 50% of its time. Such a layout will be unbalanced one and the production time

needs to be balanced. Such layout is shown in fig.

[Figure 2.4: Before line balancing]

Receiving

A (1)

A (2)

A (3)

A (4)

B (1)

B (2)

C (1)

Shipping

LLiinnee BBaallaanncciinngg

Receiving

A B C Shipping

25 pieces/hr 50 pieces/hr 100 pieces/hr

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[Figure 2.5: After line balancing]

The actual production in the line will be decided on the basis of the machine with

the maximum production capacity. The production capacity of the other machines in the

line will be adjusted through the increased in the number of machines. In this case, machine

C produces 100 units per hour, hence 100 units will be manufactured per hour with the help

of two machines B and from machines A. Thus, the line balancing for the production 100

units per hour will be done by arranging four machines of type A, two machines of type B

with one machine of type C. Thus, the idle capacity will be totally eliminated. The

arrangement is as shown in figure.

The main objective of line balancing is to distribute tasks evenly over the

workstation so that idle time of man and machines is minimized. Line balancing aims at

grouping the facilities (or tasks) and workers in an efficient pattern in order to obtain an

optimum balance of the capacities. For perfect line balancing it is essential that the output

of fastest machine is multiple of the output of the remaining other machines. But, this may

not be always possible and hence, it would be difficult to eliminate the idle capacity totally.

In such cases some other tasks are assigned to the machines remaining idle. Thus, the tasks

re grouped so that their total time is preferably equal to or a little lesser than the time

available at each work station in order to reduce idle time.

In reality the problem is not simple. The main problem arising out of such simplified

perfect line balancing is the disposal of the large volume of production. In such situation the

solution is sought with the help of the cost-benefit analysis. If the cost of over-production

exceeds the cost of idle capacity in the unbalanced line, then attempts are made to solve the

problem in some other manner as follows:

1.Another product line enabling the use of idle capacity of the first line could be run close

to it.

2.To transfer the work elements from overloaded machines to some other machines

somewhere else in the line.

3.If negligible part of some machine capacity is required to be utilized then the job may be

performed with some outside jobbing firms.

4.Alternately, machines with lower capacity utilization rate may be used to perform the jobs

of other manufacturers thorough sub-contracting.

For solving the line balancing problems, numbers of methods are available, for

example, linear programming, and dynamic programming, PERT, CPM etc. Only those

solutions should be sought which command the maximum economic benefits.

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EXPERIMENT.NO: 3

AIM: - STUDY OF COMPUTERIZED LAYOUT PLANNING

COMPUTERIZED FACILITIES LAYOUT:-

In a sense, computerized layout permits the computer to develop the diagram, based

on a heuristic program that hopefully considered enough factors for the resulting printout to

be acceptable. Often, however, the connotation of computerized layout has been much

inflated. No computer program is capable of considering all the facts, factors, and

interrelationships covered. Resolving them into a optimum layout. In fact more than one

person has said, “If I had all the data in needed for a layout computer program, I wouldn‟t

need a computer.” And herein lies the problem. Much of the real data required by most

programs is not readily available, because it is not a product of the typical accounting

system or it is too difficult to obtain. Consequently much of the data is approximated. In

all honest, however, it should be said, that if layouts are being made, by a method, with less

data than the computer requires, the result will be extremely questionable.

The computerized algorithm is an extremely powerful device for making

comparisons of alternative arrangements of activity areas, it terms of selected criteria and

available data. And it should be noted here that in most cases, the computer printout is only

an area allocation diagram it is not layout.

HISTORIC BACKGROUNG:-

The term quantitative technique has come to mean techniques that rely on are

oriented toward, mathematical statistical, and modeling approaches and problem solving.

Although the computer has been used in applying these techniques we used in plant layout

work some 20 years earlier. The advent of the computer, are its free use by researchers in

the colleges and universities, tuned on a literal flow of computerized routines.

Prior to that, a number of practitioners are researchers made attempts applying

mathematics and statistics to layout problems.

The general area of quantitative approaches to plant layout was much investigated

and discussed over the next several years, and a 1967 survey indicated that quantitative

techniques in the following list were being applied, with waiting lines the most commonly

used:

1. Waiting lines

2. Monte carols simulation

3. Transportation programming.

4. Conveyor analysis.

5. Material analysis.

6. Assignment technique.

7. Dynamic programming.

8. Transshipment programming.

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9. Integer programming.

10. Quadratic programming.

11. Traveling salesman technique.

12. Level curve model.

For almost every technique the consultant group was by far the greater used, in most

cases by a margin of two-to-one. The major development during the above period was the

first layout program capable of printing out a rough version of an area allocation diagram,

the program called CRAFT.

WHY QUATITATIVE TECHNIQUES:-

The facility design process is not as simple a matter as it is seem. Although it is

often passed over a lightly, given little technical support, and frequently carried out by

people almost totally unaware of its complexity, it is fraught with dangers of both omission

and commission. For instance, consider these characteristics of the facility design problem:

1. Its myriad interrelationship

2. Its overall complexity.

3. The great number of factors.

4. The wide range of factors.

5. The intangibleness of many factors.

6. Flexibility requirements.

7. The human support of the layout problem.

8. The importance of experienced judgments.

9. Personal preferences.

10. The economic consequences of poor layout.

It is because of such characteristics that the layout problem has been treated largely

by non-quantities, heuristic methods. However, on behalf of these techniques, it must be

said that they are extremely useful and sufficiently successful for analyzing a large majority

of layout handling problems. In fact, they are far beyond the means used in most facility

planning done every today.

More often than not, such assumptions were false, unrealistic, or deceptively

simplified. Or, it might be said that the complicating, real world aspects were wished away

– with the inevitable result that the answer obtained were actually an unanswered to a non-

problem. Some of the misleading assumptions might have been:

1. All departments are square.

2. Material flows between the centers of departments.

3. Material handling cost is directly proportional to distance.

4. All data on material flow are known, and are deterministic in nature.

5. Waste or scrap material need not be considered.

6. All travel is in two dimensions.

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The above is not mean to discredit attempts to design layouts by computers, but to

warn the user of the relative validity of results and to encourage him to obtain as much valid

data as possible. If a serious attempt is made to obtain good data on most of the relevant

factors, the result of a computerized layout algorithm can be extremely useful in:

1. Exploring a great many potential relationships not otherwise accessible.

2. Permitting the designer to learn from data collection process.

3. Providing an insight into the problem by watching the print-out process.

4. Better defining the problem, this is necessary for computerization.

CRITERIA FOR A COMPUTERIZED LAYOUT PROGRAM:-

In view of the difficulties in developing layout models, and in improving their

usefulness, it seems wise to consider desirable criteria for such a model. The following list

of desired criteria came out of a seminar discussion and evaluation of several existing

models:

1. Reliability.

2. Use of real data

3. Ability of weight inputs.

4. Elimination of subjective evaluation of solutions.

5. Better configurations of activity centers.

6. Allowance for fixed activity locations.

7. Honoring of building restrictions.

8. Usability for multi story layouts.

9. Consideration of cost incurred in generation of alternate layouts.

10. Provision of more realistic cost evaluation.

11. A minimum of restrictions to retain flexibility.

12. Ability to extract desirable features from a specific layout for insertion into another.

13. A more realistic graphical print out.

14. Elimination of manual adjustment of graphical print out.

15. Ability to handle undesirable interrelationships.

16. Applicability to detail layout.

In spite of above admonitions, the introduction of the quantitative techniques and

the advent of the computer have encouraged experiments design problem.

COMPUTERIZED LAYOUT PROGRAMS:-

In this section, four of the more commonly known and widely used programs are

described and discussed briefly in chronological orders of their appearance in the literature.

The basic concepts of each are as follows:

CRAFT - interchanges activity locations in the initial layout to find improved solutions

on material flow. Successive interchanges lead to sub-optimum least cost layout.

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CORELAP - locates the most related activity, and then progressively adds other

activities, based on rated closeness desired, and in sized until all activities have been placed.

ALDEP - selects at random and locates the first activity. Subsequent activities, in

required size, are selected and place: (a) according to closeness desired, or (b) at random, if

no significant relationships are found. Alternative layouts generated and scored.

PLANET - utilizing interdepartmental flow data, computes the “penalty” cost associated

with separating departments. Their heuristic algorithms are available for generating

alternative configurations to be manually evaluated and adjusted.

INPUT REQUIRMENTS:-

All four programs require the fundamental inputs of relationships and space.

Craft uses material flow data as the base for developing closeness relationships in

terms of some units of measurements between pairs of activity to form a matrix for the

program.

Planet requires two basic types of input data: department information and material

flow in formations. Each is identified and the area requirements stated.

Such characteristics of material size, shape, weight and durability must be

considered in selection handling method and estimated cost: before the cost estimate can be

made, the method must be selected. And finally, there must be provided the sequence of

movements associated with each part.

Corelap and aldep – the other tow programs use the vowel-letter closeness

relationships as input data, based on material flow and other factors.

Corelap requires the amount of space for each activity to be known and also a max

building length-to-width ratio. Aldep requires the size of the each activity and a

representation of building dimensions, including assignments of specific building features,

such as aisles and stairwells, and reassigned activity locations.

HOW THE PROGRAM WORKS:-

Craft computes the product of the flow, handling cost, and distance between centers

of activities. Then it considers exchanges between locations and examines two-ways and

three way exchanges. An exchange involving the greatest cost reduction is made, and a

new total cost determined. The process is repeated until no significant cost reduction is

found.

Corelap calculates which of the activities in the layout is the busiest or most widely

related. Sums of each activities relationships with other activities are compared, and the

activity with the highest total is located first in the layout matrix. Next, an activity that

must be close to it is selected and placed as nearly adjacent as possible.

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Aldep uses a preference table of relationship values to calculate the scores of a

series of randomly generated layouts. A modified random selection technique is used to

generate alternate layouts. The first activity is selected and located at random. Next, the

relationship data are searched to find an activity with a high relationship to the first. It is

placed adjacent to the first. If none is found, a second activity is selected at random and

placed next to the first. This procedure is continued until all activities are placed. This

process is repeated to generate another layout.

Planet utilizes information about the material flow patterns, with the algorithm

establishing a layout by asking:

1. Which department should be selected for placement next?

2. Where should this department be placed/

It then fixes each department in the layout in such a way as to keep the material

handling cost as low as possible. Three alternative methods evaluate the relationships

between departments not yet selected pairs for placement and those that have been selected.

Strong interrelationships between department pairs or within a department group will imply

early selection.

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HOW THE PROGRAMS PRESENT THE LAYOUT:-

[Figure 3.1: General concept of selected layout algorithms (Adapted from Muther and

McPherson.)]

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Craft prints a layout in basic rectangular form. Each activity appears on the

printout, as a certain number of square feet or square meters. Craft‟s output indicates

activities by letter. While the resulting overall configuration is rectangular, individual

activity shapes tend to be irregular and must be adjusted into practical shapes.

Corelap prints a layout of facilities in an irregular format. Neither the individual

activities nor the total layout is in any practical rectangular shape. So further adjustment is

imperative for a workable layout.

Aldep prints a layout contained within a give rectangular area boundary, although

individual activities tend to be irregularly shaped. Activates are placed or located by means

of vertical scan, so activity shapes tend to be rather elongated. As with the other programs,

each activity number represents a certain portion of the activities total space.

Planet, like coelap, prints a layout of facilities in an irregular format. The program

attempts to keep a department shape somewhat square, in order to avoid elongated shapes.

However, relatively small departments may not appear in a desirable shape. Final layouts

are some what easier to interpret with this notational convenience. If a layout into strips

and print the strip on successive output pages.

It can be seen that some of the computer print outs must be adjusted into an

acceptable rectangular shape. While this could be done by the computer, it would take a

longer routine. Besides, the adjustment process permits the analyst to exercise his

experienced judgment in making final alterations, prior to working on the detailed layout.

ADVANTAGES AND LIMITATIONS OF PROGRAMS:-

Participants in the Seminar previously referred to list the advantages and limitations

of the four programs discussed here. The results are given in table.

As suggested previously, there are several other layout algorithms, some propriety,

and some available for general use. Undoubtedly there will be more, as future experiments

try to develop more accurate and more easily applicable programs.

COMPARISON OF COMPUTERIZED LAYOUT TECHNIQUES:-

With the several layout and design models available, it is only natural for the analyst

to ask which is best. Several researchers have attacked this problem, and reported on

comparisons of some of the more widely known programs. One of the studies is abbreviated

below, and illustrated in table.

Since CRAFT has the capability to evaluate a layout on a quantitative basis, we

decided to appraise the output of CORELAP and ALDEP through the use of the appraisal

portion of CRAFT, and further, to let CRAFT try to improve on the best of CORELAP and

ALDEP output. We, therefore, fed the output layouts to CRAFT. The basic materials

handling data expressed in the CRAFT input remained invariant.

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CRAFT:-

ADVANTAGE:-

1.Permits fixing specific location.

2.Input shapes can vary.

3.Short computer time.

4.Mathematically sound.

5.Can be used for office layouts.

6.Can check previous iterations.

7.Cost and savings printed out.

LIMITATIONS:-

1.Requires hand adjustment.

2.Program tends to be “short sighted” may not find best answer by switching two or three

departments at a time.

3.Departments switched must be 1) the size, 2) adjacent to each other and 3) border on a

common department.

4.Input data needs careful structuring.

5. Letter designation cumbersome.

6.Does not generate an initial layout.

7.Better adapted to rearrangements.

8.Limited to 40 departments.

CORELAP:-

ADVANTAGE:-

1. Easy to get going on computer.

2. Generates new layouts.

3. Input and output terms are the same.

4. Based on the Relationship Chart.

5. Each step visible during layout development.

LIMITATION:-

1.Cannot specify fixed activity locations.

2.Does not calculate cost.


4.Irregular shaped layout.

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ALDEP:-

ADVANTAGE:-

1. Can fix specific locations with confined of space available.

2. Solution is within specified area.

3. Many alternatives are developed.

4. Honors most interrelationships.

5. Has multi-level capability.

DISADVANTAGES:-

1.Cost of movement not calculated.

2.Undesirable (X) relationships not honored.

3.Evaluation or scoring method questionable.

4.Difficulty in evaluating production processes.

5.Mandatory space configurations not taken into account.


PLANET:-

ADVANTAGES:-

1. Based on from to chart.

2. Used M.H. cost for a specified method of handling for each move in a predetermined

operation sequence.

3. Requires interaction between computer routine and engineer, to exercises his judgment.

4. Applicable to any problem involving quantifiable relationship between activities.

5. Can fix specific activity locations and building features.

6. No input layout required.

LIMITATIONS:-

1. Primarily useful for production layouts.

2. In need of actual application and experimentation.

3. Input data needs structuring.

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EXPERIMENT.NO: 4

AIM: - TO STUDY OF FLOW PATTERNS FOR MATERIAL IN PRODUCTION

LINES & CASE STUDY ON LINE BALACING

In almost any enterprise can think of productivities best served by an efficient flow

of the laments that move through the facility. This is just as important in a library, grocery

store, post office, bus station, hospital, or restaurant as it is in a manufacturing plant. In

each case, elements entering the system are processed and leave the system in a change

condition and primary objectives in planning an efficient enterprise is to provide for

element flows that will facilitate the efficient movement of the elements through the

activities. In fact, one of the nation‟s largest designers and constructors of industrial

buildings has said.

Smooth out materials flow and you automatically trim production costs. A plant is

actually nothing more than a great collection of machinery-receiving, assembling, shipping

and storage areas linked together by materials handling devices of one kind or another. No

matter how handsome a plant may be form the outside, no matter how clean and functional

it may look on the inside, no matter how thoroughly it is tooled its production efficiency

will depend upon the swift, smooth flow of material throughout the plant.

ADVANTAGES OF PLANNED MATERIAL FLOW:-

Too much emphasis can not be placed on the importance of determining the most

efficient plan for the flow of material through facilities. It is precisely at this point, for

however, that many manufacturing plans fall short.

Only by designing a master flow pattern, early in the planning process, can one be

sure that all subsequent planning efforts are directed toward a worthwhile goal. This is not

to say, however, that a flow pattern devised early in the planning layout.

A will not be subject to changes as planning progresses toward the final, a well

conceived and carefully planned material flow pattern will behave many a cages, and a

good flow pattern will go a long way toward achieving several of the objectives of facilities

design, as stated in Chapter 1 some of the advantages are as follows :

1. Increased efficiency of production productivity.

2. Better utilization of floor space.

3. Simplified handling activities.

4. Better equipment utilization less idle time.

5. Reduced in process time.

6. Reduced in process inventory.

7. More efficient utilization of work force.

8. Reduced product damage.

9. Minimum accident hazards.

10. Reduced walking distances.

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FACTORS FOR CONSIDERATION IN PLANNING MATERIAL FLOW:-

Before the actual task of designing a flow pattern can be undertaken, man factors

must be considered, which determine some of the flow pattern, or its relationship to the

other phases of the layout planning project. Not all of them can be properly consideration at

one time, nor they can be adequate covered in this chapter.

MATERIAL OR PRODUCTS:-

Of particular interest are material related factors affecting volume, space and

handling

VOLUME OF PRODUCTION:-

The desired sales and production volume were discussed in chapter 3 as related to

the sales department and top management contributions to the planning process. No single

factor is of greater importance to lay out planning than the quantity of material to be

proceeding and the effect of this on production processes.

NUMBER OF PARTS, PRODUCTS, OR ELEMENTS:-

Think for a moment of the differences in complexity of the flow pattern of such

varying situation as manufacturing or providing the following products and services.

1. Yo-yos 5. Radios 9.Campus

2. Foot stools 6 Typewriters 10.Abank

3. Bicycles 7. Automobiles 11. A hospital

4. Refrigeration 8. Aircraft 12. A post office

NUMBER OF OPERATION:-

The number of operations on each part or at each activity center is also a major

factor in planning the flow pattern. For instance, a part requiring only one or two operations

will probably require only on or two machines and consequences little space and few

people to perform the work. And similarly the flow between activities in a warehouse is less

complex than that through a hospital.

STORAGE REQUIREMENT:-

In nearly every type of enterprise, there will be a need for the storage of work

awaiting processing or awaiting movement to another area after processing.

MOVES:-

The following area few move characteristics worthy of preliminary though

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CROSS TRAFFIC:-

The potential interference with the orderly flow of elements through the enterprise

caused by cross traffic should be a major concern back tracking crossed flow lines etc.

should be avoided.

REQUIREMENT FLOW BETWEEN WORK AREAS:-

The flow of work from one work place to the next will be an important factor in

determining the flow pattern. Complications may arise if the part must go out of line to

another area in the course of its processing.

LOCATION OF RECEIVING AND SHIPPING ACTIVITY:-

These points are usually the beginning and end of the material flow pattern. The

receiving activity should have a high priority in orienting the flow pattern in relation to the

building.

At the same time, the shipping activity should be located in close relation to

transportation facilities shows some of the possible interrelationships between receiving,

shipping, transportation. Also, there are other factors to be located in separate positions on

the layout, or if they should be combined in to one receiving and shipping area.

HANDLING METHODS:-

Materials handling plans and equipment may have been given some thought, in a

general way, prior to the establishment of an overall flow pattern. If this is true, it will be an

important factor in the final design of the flow pattern.

PROCESSES:-

The mfg. processes or activity centers are the reason for flow patterns

SEQUENCE OF OPERATIONS:-

As pointed out in the production routing lists the operation to be performed on each

component of a product. Frequently this sequence of operation physical order in which they

are to be performed.

SPECIFIC REQUIREMENT OF ACTIVITIES:-

1. Heat heating-ventilation, fire protection

2. Painting ventilation, fire protection, heating.

3. Forging ventilation, heat removal, noise, and vibration damping.

4. Precision assembly-air conditioning.

5. Executive work quiet

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QUANTITY OF EQUIPMENT:-

Since each piece of equipment or activity center will occupy a square feet, so not

only the sequence of operations but the no. of machines and pieces of equipment will have

an effort on the flow pattern.

NUMBER OF SUBASSEMBLIES:-

1. To simplify the handling during final assembly.

2. To shorten the final assembly line.

3. To separate from the line, equipment that the some reason would interface with the line.

4. To allow for testing a sub assembled unit before introducing it into the final assembly.

5. To allow for volume production of a subassembly that is destinated for several different

products

BUILDING:-

Building type: if an existing building is to be used, the layout may have to be fitted

into it without major building alterations, where as if a new building is being to be

considered, it should be a planned around the optimum layout.

NUMBER OF FLOOR:-

In new building single stories are more common than multiple floors the number of

floor has a considerable influence on the flow pattern, since materials may have to be

moved from floor to floor.

AISLE AREA:-

The aisle area in a plant is intended for personal traffic and material routing, but is

often used for other purposes. There is a tendency to cut down the aisle by using part of

their allocated area for such things as stock and additional equipment.

DESIRED LOCATION OF DEPARTMENTS:-

1. No. of pieces to be handled per time unit.

2. Rough weight of each piece.

3. Weight of stock removed from each piece at each operation.

4. Distance over which rough pieces, semi finished pieces or scrap must be moved.

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SITE:-

The plot of ground upon which a facility stands frequently affects the building

configuration and therefore the flow pattern.

TOPOGRAPHY:-

The lay of the land, in terms of contour, shape and size as well as sub soil condition

will affect the building.

TRANSPORTATION MODES AVAILABLE:-

Some attention should also be given to the transportation alternatives. In the long

run a decision to install a new transportation facility might save many thousands of dollars

over the use of existing facilities.

TRANSPORTATION FACILITIES AVAILABLE:-

Although the preceding paragraph implies that transportation facilities should be

designed, rather than simply accepted. This can happen when the opportunities are limited

either by volume requirements or by favorable proximity of suitable existing transportation.

EXPANSION POSSIBILITIES:-

When designing the material flow attention should be given to the direction in

which the building might be extended. This could affect the orientation of the flow pattern

within the proposed facilities, or on the plant site. The flow pattern should be so designed

that extension in desirable directions is body possible and body logical

PERSONNEL:-

1. WORKING CONDITION:-

A. ILLUMINATION:-

1. Lighting should be adequate and suited to the job.

2. Use may be made of natural lighting.

B. VENTILATION:-

1. Ventilation must be adequate in all areas.

2. Lavatories, locker rooms smoking rooms should be located for convenient access and

provided with good ventilation.

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C. HEATING:-

1. Adequate heat must be provided for every work area.

D. NOISE AND VIBRATION:-

1. Proper location of equipment.

2. Proper selection or design of equipment

E. HEALTH AND SAFETY:-

1. Aisle location and widths 5.Floor load limits

2. Equipment location 6.Light

3. Machine and conveyor guards. 7. Ventilation

4. Type of flooring

FLOW PLANNING CRITERIA:-

Over a period of years those who have dealt with the problems of material flow have

come to a no. of general conclusion about certain aspects of the flow.

1. Optimum material flow.

2. Continuous flow.

3. Straight line flow.

4. Minimum flow between related activities.

5. Heavy material to move least distance.

6. Minimum of back trickling

7. Minimum of material in work area.

8. Material at point of use.

9. Related activities in proper proximity to each other

10. Amenable to expansion in pre planned directions.

11. Receiving and shipping in proper relation to

a. Internal flow

b. External transportation facilities existing proposed

12. Activates with specific location requirements situated in proper spots

a. Production operation

b. Production services

c. Administrative services

13. Production control aspects easily attainable

14. Quality control aspects easily attainable

15. No apparent violations of health or safety requirements.

16. Consideration given to multi floor possibilities

a. Present

b. Future

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GENERAL FLOW PATTERNS:-

The experienced layout engineer recognizes that a majority of material flow

problems fit into one of a relatively small no. of general flow patterns.

1. STRAIGHT LINE:-

Applicable where the product process is short, relatively simple and contains few

components of production equipment.

2. SERPENTINE OR ZIGZAG:-

Applicable where the line is longer than it would be practicable to allocate space for

and therefore bends back on it to provide a longer flow line in an economical building area.

3. CIRCULAR:-

Applicable when it is desired to return a material or product to the place it such as

for a foundry flask and where shipping and receiving are at the same location.

4. ODD:-

Angle-no recognizable pattern, but very common

(a) When the primary objective is a short flow line between a group of rated areas.

(b) Where handling is machined

(c) When space limit will not permit the another pattern

(d) Where permanent location of existing facilities demand such a pattern.

DESIGNING THE FLOW PATTERN:-

The task now remains of actually developing the flow pattern from the information

and data accumulated. Although there is no set of procedure for planning the material flow

pattern it will be found helpful to proceed in an orderly manner.

1. Identify and review all elements that will flow through the facility such as

a. material

b. scrap and waste

c. manpower

d. equipment

e. information

2. Collect all necessary

CASE STUDY ON LINE BALANCING:-

The assembly line for manufacturing mixes in a company is considered. The

precedence diagram of the assembly line is shown in fig. the detail of the work element,

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their processing time are shown in table. The production volume per shift is 300 units.

Design the assembly line using ranked positional weight (RPW) method such that the

balancing efficiency is maximized.

15.30 43.30 61.40 65.00 57.30 3.30 2.00 4.50 20.30

1 2 3 4 5 6 7 8 9 62.50

21

10.50

22

19

23 95.70

94.10

20

32.30

10 11 12 13 15 16 17 18

17.50 9.40 10.00 7.00 30.00 10.50 6.30 25.00

Task no. Description of the task Standard time (sec.)

1 Fixing motor on to the adaptor 15.30

2 Fixing the base 43.30

3 Chord connections and wire dressing 61.40

4 Mechanical testing 65.00

5 Electrical testing 57.20

6 Fixing tunnel 03.30

7 Fixing motor support 02.20

8 Relay connections 04.50

9 Inverting bottom plates and screw tightening 20.30

10 Drilling and reaming 17.50

11 Pressing the brass bush to cup 09.40

12 Applying the bond 10.00

13 Fixing the circular ring 07.00

14 Jar correction 09.00

15 Rivet preparing 30.00

16 Riveting 10.50

17 Handle assembly 06.30

18 Blade assembly 25.00

19 Overall testing 94.10

20 Cleaning and buffing 32.30

21 Dome packing 62.50

22 Thermocole packing 10.50

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23 Overall packing 95.70

DETAILS OF PROCESSING WORK ELEMENTS:-

Task no. Immediate predecessor Duration(sec.) Positional weight

1. - - 15.3 567.5

2 1 - 43.3 552.2

3 2 - 61.4 508.4

4 3 - 65 447.5

5 4 - 57.3 382.5

6 5 - 3.3 325.2

7 6 - 2.0 322.2

8 7 - 4.5 320.2

9 8 - 20.3 315.7

10 - - 17.5 410.8

11 10 - 9.4 393.3

12 11 - 10.0 383.9

13 12 - 7.0 373.9

14 - - 9.0 375.9

15 13 14 30.0 366.9

16 15 - 10.5 336.9

17 16 - 6.3 326.4

18 17 - 25.0 320.1

19 9 18 94.1 295.1

20 19 - 32.3 128.0

21 19 - 62.5 168.7

22 21 - 10.5 106.2

23 20 22 95.7 95.7

DATA IN DESIRED FORMAT:-

Production volume/shift=300 units

Therefore the cycle time, CT=28800 sec/300=96 sec.

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RESULT OF DESIGN OF ASSEMBLY LINE:-

Station

no.

List a Task

selected

Unassigned

cycle time(sec.)

1 - - 96

1,10,14 1 80.7

2,10,14 2 37.4

10,14 10 19.9

11,14 11 10.5

12,14 12 05.5

2 - - 96.0

3,13,14 3 34.6

13.14 14 25.6

13 13 18.6

3 - - 96.0

4,15 4 31.0

15 15 1.0

4 - - 96.0

5,16 5 38.7

6,16 16 28.2

6,17 17 21.9

6 6 18.6

7 7 16.6

8 8 12.1

5 - - 96.0

9,18 18 71.0

9 9 50.7

6 - - 96.0

19 19 1.9

7 - - 96.0

20,21 21 33.5

20,22 20 1.2

8 22 22 85.5

9 - - 96.0

23 23 0.3

Sum of the unassigned cycle time=171.8

Cycle time=96 secs.

No. of stations=9

Balancing efficiency = (1-suact)/ (ct*n)*100 =80.11%

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EXPERIMENT.NO: 5

AIM: - WRITE-UP ON GROUP TECHNOLOGY & PROCESS PLANNING

INTRODUCTION:-

It has always been a common practice to group similar types of work together, when

one deals with a variety of assignments, with the intention of reducing the total work

because of commodities of approach and work procedures involved.

For quite sometime this technology has been applied in process planning for small

and medium batch manufacturer. Both manufacturing is estimated to be the most common

form of production in the United State constituting perhaps 50 % or more of the total

manufacturing activity. There is growing need to make batch manufacturing more efficient

and productive. Also, there is an increasing trend to achieve a higher level of interrogation

of the design and manufacturing functions in a firm, one of the approaches that are directed

at both of this objective is GROUP TECHNOLOGY (G.T.)

“GROUP TECHNOLOGY” is a manufacturing philosophy in which similar parts

are identified and grouped together to take advantage of their similarities in manufacturing

and design. It deals with identification of similar and groups them for the purpose of

manufacturing and design.

For, example a plant producing 10,000 different part numbers may be able to group

the vast majority of these parts into 50 or 60 district families. Each family would posse‟s

similar design and manufacturing, characteristics. Hence, the processing of each member of

a given family would be similar and this results in manufacturing efficiencies. These

efficiencies are achieved by arranging the production equipment into machine groups or alls

to facilitate work flow. In product design, there are also advantages obtained by grouping

parts into families. These advantages tip in the classification and coding of parts.

Parts classification and coding is concerned with identifying the similarities among

parts and making these similarities to a coding system. Parts similarities are of two types.

(i) Design attributes (such as geometric shape and size)

(ii) Manufacturing attributes (the sequence of processing steps required to make the

part)

Group Technology and parts classification and coding are closely related Group

Technology is the underlying manufacturing concept, but same form of parts classification

and coding is usually required in order to implement G.T. This technology streamlines

procedure and is amenable to computerization, and therefore, it would go a long way in

forming the basis of integrated manufacture and thus would prove an important step in

indicating automation in small and medium batch manufacture.

In various products the components would be grouped on the basis of similarity of

their shapes and manufacturing procedures. If components are coded according to such

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characteristics their retrieved would be convenient which would not only help in avoiding

duplication of efforts but also in enlarging the both sizes of manufacture, enabling

production in time and cost involved.

HOES G.T. IS APPLIED:-

The formation of groups in small and medium batch manufacture is not an easy task.

One of the ways of forming such groups would be VISUAL. This will for experience and

can be applied when the numbers of products subsequently, their components is not very

large.

Production Flow Analysis (P. F. A) Is another methodology in G.T. In this analysis,

grouping of part is done in terms of the manufacturing sequence.

GUIDELINE FOR IMPLEMENTING G.T.:-

1. Collect a complete, variety of components being manufactured in the company.

2. Get an estimate of the quantity to be produced for each, variety over a period of time.

This

period will depend on the policies of manufacture and stocking the requirements.

3. Obtain the process sheet for each component.

4. For implementation of G.T. exclude special operations e.g., heat treatment, painting,

forging etc.

5. Try to plan the production as all the parts of a family in one all. This would be acceptable

is these machineries work inexpensive, otherwise such machines would be utilized by

other cells too. This would enable flexibility in labour.

6. The layout should be such as to permit a redistribution of load amongst various alls

whenever fluctuations in load arise.

7. Study the data on operations their sequences for various components, the quantity

required,

the machine tool apaixties the setup time, and the machining times based on this adulate

the workload on each machine tool.

8. Collect the components which use,

(a) The same, sequence of machine tools.

(b) Same machines.

PART FAMILIES AND CLASSIFICATION & CODING:-

PART FAMILIES:-

A part family is a collection of parts, which are similar either because of geometric

shape and size or because similar processing steps are required in their manufacture. The

parts within a family are different, but their similarities are close enough to merit their

identification as members of the part family.

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One of the big manufacturing advantages of grouping work parts into families can

be explained with reference to fig 5.1 and 5.2. Fig 5.1 shows a process type layout for batch

production in a machine shop. The various machine tools are arranged by function. There is

a lathe section, milling machine section, drill press section, and so on. During the

machining of a given part, the work price must be moved between sections, with perhaps

the same section being visited several times. This results in a significant amount of material

handling, a large in process inventory, usually more setups than necessary, long

manufacturing lead times and high cost.

Fig. 5.2 shows a production shop of equivalent capacity, but with the machines

arranged into alls. Each all is organized to specialize, in the manufacture, of a particular

part family. Advantages are gained in the form of produced work piece handling, lower

setup times, less in process inventory and shorted lead times.

[Figure 5.1: Process type layout]

[Figure 5.2: Group technology layout]

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There is a problem of grouping parts in to families. There are three methods for

solving this problem.

1. Visual inspection

2. Classification & coding by examination of design and production data.

3. Production flow analysis (P. F. A.)

1. VISUAL INSPECTION:-

The visual inspection method is the least sophisticated and least expensive method.

It involves the classification of parts into families by looking at either the physical parts or

their photographs and arranging them into similar groupings.

Although this method is generally considered to be the least accurate of the three,

one of the first major success stories of G.T. in the United States made the change over

using the VISUAL METHOD classification and coding by explanation of design and

production data.

This second method involves classifying the parts into families by examining the

individual design, and manufacturing attributes of each part. The classification results in a

code number that uniquely identifies the part‟s attributers.

This classification and coding may be arrived out on the entire list of active parts of

the firm or some sort of sampling procedure may be used to establish the part families.

As mentioned previously the three methods of identifying part families all

requirement a significant investment in time and manpower. The most time consuming and

complicated of the there methods is parts classification and coding.

The need for classification and coding systems for identification and retrieval of

similar design has been well emphasized in an earlier discussion. This would lead to variety

production, standardization and design nationalization.

The major benefits of a code designed classification and coding system for group

technology have been summarized as follows.

1. It facilitates the formation of part families and machine tools.

2. It permits quick retrieval of designs, drawings and process plans.

3. It reduces design duplication.

4. It provides reliable work piece statistics.

5. It facilitates accurate estimation of machine tool requirement and logical machine

loading.

6. It permits nationalization of tooling setups, reducer setup time, and producers

production through time.

7. It allows nationalization and improvement in tool design.

8. It aids production planning and scheduling procedures.

9. It facilitates NC part programming.

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2. TYPES OF CLASSIFICATION & CODING SYSTEM:-

Although it would seem from the forgoing list that nearly all department in the firm

benefit soon a good parts classification and coding system , the two main functional areas,

that use the system are design and manufacturing accordingly parts classification.

1. Systems based on part design attributes.

2. Systems based on part manufacturing attributes.

3. Systems based on both design and manufacturing attributes.

There are two basic structures.....

HIERAROCHICAL STRUCTURE:-

In this code structure the interpretation of each succeeding symbol depends on the

value of pre coding symbols. For example consider a two digit code, such as 15 to 25

suppose that the first digit stands for the general part shape. The symbol of means round

work part and 2 means flat rectangular geometry. The advantage of this structure is that

more information can be contained in the code.

CHAIN TYPE STRUCTURE:-

In this type of code, the interpretation of each symbol in the sequence is fixed. It

does not depend on the value of the proceeding symbol. Some parts classification and

coding systems use a combination of the hierarchical & chain type structure.

Four classification and coding systems will be discussed in the following sub

sections.

1. The Opitz System.

2. Multiclass System.

3. Vuoso System

4. Mixclass System.

1. THE OPITZ CLASSIFICATION SYSTEM:-

The Opitz system is of historical interest because it was one of the first published

classification and coding schemes for mechanical parts. The parts classification and coding

system was developed by H. Opitz of the University of Aachen in West Germeny.

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[Figure 5.3: Basic structure of Opitz system of parts classification and coding]

The Optiz coding system uses the following digit sequence.

12345, 6789 ABCD.

The basic code consists of nine digits, which can be extended by adding four more

digits.

The first five digits 12345 are called the “Form Code” and describe the primary

design attribute of the part. The next four digits 6789, constitute the “Supplementary Code”

which indicates some of the attributes that would be of use to manufacturing. The extra four

digits ABCD are informed to as the “Secondary Code” and are intended to identify the

production operation type and sequence.

The complete coding system is too complicate to provide a comprehensive

description here.

2. MULTICLASS SYSTEM:-

Multi class is a current commercial product offered by OJR, the Organization for

Industrial Research. Multi class is a classification and coding system developed by the

organization for Industrial Research.

Up to nine different types of components can be included within a single multi class

software structure. Multi class soft wears a hierarchies or decision three coding structure in

which the succeeding digits depend on values of the previous digits. The coding structure

consists of up to 30 digits. The 30 digits are divided into two regions, one provided by OIR

and the second designed by the user to meet specific needs and requirements.

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[Figure 5.4: Code determine pan of example & by multiclass system]

3. VUOSO SYSTEM:-

A typical example of such a hierarchy‟s code system is Vuoso. Suppose there is a

brass bar 30mm in diameter and of 100 mm length, with a blind threaded hole in axis, the

its code would be 2116.

4. MIXCLASS SYSTEM:-

This is the Metal Institute Classification System was developed in Holland. Many

functions in design, manufacturing and management can be structurized and automated

with this system.

3. PRODUCTION FLOW ANALYSIS:-

INTRODUCTION:-

Production flow analysis is a method for identifying part families and associated

grouping of machine tools. It does not use a classification and coding system and it does not

use part drawings to identify families.

However, the disadvantage of using production flow analysis is that it provides no

mechanism for nationalizing the manufacturing routings. It takes the route sheets the way

they are with no consideration being given to whether the routings are optional or consistent

or even logical.

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P.F.A. PROCEDURE:-

The procedure in production flow analysis on be organized into the following

steps...

.1. DATA COLLECTION:-

The first step in the P.F.A. procedure is to decide on scope of the study and to

collect the necessary data. Additional data, such as lot size time standards and annual

production quite might be useful for designing machine cells of the desired productive

capacity.

2. SORTING OF PROCESS ROUTINGS:-

The second steps are to arrange the parts into groups according to the similarity of

their process routings.

3. P.F.A. CHART:-

The processes used for each part are next displayed graphically on a P.F.A. Chart.

4. ANALYSIS:-

This is the most subjective and most difficult step in production flow analysis.

These analysis help in arranging facilities and groups of component so as to minimize

movement and improve the utilization of facilities.

[Figure 5.5: Matrix-operations components]

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[Figure 5.6: Rearranged matrix]

[Figure 5.7: Grouping based on production flow analysis]

COMMENT ON P.F.A.:-

The weakness of production flow analysis is that the data used in the analysis are

designed from production route sheets. The process sequences from these route sheets have

been prepared by different programme planners and these differences are inflected in the

route sheets.

MACHINE CELL DESIGN:-

INTRODUCTION:-

Whether part families and machine groups have been determined by parts

classification and coding or by production flow analysis, the problem of designing the

machine cells must be solved in this section we consider some of the aspect of this

important problem in group technology.

THE COMPOSITE PART CONCEPT:-

Part families are defined by the fact that their members have similar design and

manufacturing attributers. The composite part concept takes this part family definition to its

logical conclusion.

A machine alls would be designed to provide all seven machining capabilities,

machines fixtures, and tools could be setup for efficient flow of work parts through cells. A

part wills all seven attributers, such as the composite part, we go through all seven

processing steps.

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TYPE OF CELL DESIGN:-

The term cellular manufacturing is some times used to describe the operation of a

group technology machine cell. Machine cells can be classified into one of the following

allegories, according to the member of machines and the degree to which the material flow

is mechanized between the machines.

1. Single Machine Cell

2. Group machine cell with manual handling.

3. Group machine cell with Semi integrated handling.

4. Flexible manufacturing system (F.M.S.)

1. SINGLE MACHINE CELL:-

AS its name indicates, the single machine cell consists of one machine and

supporting fixtures to make on or more part families.

2. GROUP MACHINE CELL WITH MANUAL HANDLING:-

The group machine cell with manual handling is an arrangement of make that one

machine and collectivity to produce one or more part families. This allows many of the

benefits to group technology cellular manufacturing to the achieved without the expense of

arranging equipment in the shop. Obviously, many of the material handling benefits of G.T.

are not realized with this organization.

3. GROUP MACHINE CELL WITH SEMI INTEGRATED HANDLING:-

The group machine cell with semi integrated handling uses a mechanized handling

system, such as a conveyor, to move parts between machines in the cell.

4. FLEXIBLE MANUFACTURING SYSTEM:-

The flexible manufacturing system is the most highly automated of the group

technology machine cells.

DETERMINING THE BEST MACHINE ARRANGEMENT:-

Determining which type of machine cell to use and the best arrangement of

equipment in the cell should be based on work processing requirements. The important

factors include:-

1. Volume of work to be done by the cells per year and the amount of work required per

part.

2. Variations in process routing of the parts:

This determines the work flow.

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3. Part, Size, Shape, Weight and other physical attributors

These factors determine the size and type of material handling and processing

equipment that be used.

(i) Develop the form to chart from part routing data.

The data contained in the chart reflect numbers of parts moves between the

machines, in the cell.

(ii) Determine the “To from ratio” for each machine.

This is accomplished by summing up all of the “to” trips and “from” trips.

(iii) Arrange machines in order of increasing to/from ratio.

The notion is that machines that have a low ratio receive work from few other

machines in the cell but distribute work to many machines.

ADVANTAGES OF GROUP TECHNOLOGY:-

1. PRODUCT DESIGN BENEFITS:-

In the area of product design, the principal benefit derives from the use of a parts

classification and coding system.

2. TOOLING AND SETUPS:-

Group technology also tends to promote standardization of several areas of

manufacturing two of these areas are tooling and setups.

3. MATERIAL HANDLING:-

Another advantage in Manufacturing is a production in the work part move and

waiting time. The group technology machine layouts lend themselves to efficient flow of

materials through the shop.

4. PRODUCTION AND INVENTORY CONTROL:-

Several benefits to a company‟s production and inventory contest function as a

consequence of group technology.

5. PROCESS PLANNING:-

Proper parts classification and coding lead to an automated process planning system.

Even without automated process planning system reductions in the time and cost of process

planning still is accomplished. This is done through standardization.

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6. EMPLOYEE SATISFACTION:-

The machine cell often allows parts to be processed from raw material to finished

stage by a small group of workers. The workers are to visualize their contribution to the

firm. This tends to cultivate an improved workers attitude and higher lead of job

satisfaction.

DISADVANTAGES OF GROUP TECHNOLOGY:-

1. The disadvantage of Group Technology in the cost of its implementation should also be

carefully considered.

2. Morever, the entire production of the company cannot be put under the umbrella of group

production.

3. Further, the range of product and their mix could constantly fluctuate.

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EXPERIMENT.NO: 6

AIM: - WRITE-UP ON FLEXIBLE MANUFACTURING SYSTEM

DEFINITION:-

FMS is an integrated approach to automating a production operation. The primary

characteristics of FMS are that together automated production machines and materials

handling system FMS is designed to be flexible so that it can fabricate a variety of different

products of relatively low volumes.

INTRODUCTION:-

Today‟s customer market has compelled manufacturers to reduce delivery times and

quote competitive prices. The need to meet specific customer requirements calls for

considerably flexibility in the working of mfg system.

Before that what is the mean by flexibility? Amount by which the system can

perform without much re-tooling or re-positioning. So requirements that the modern

manufacturing facility has to meet are:

1. High productivity

2. Shorter throughput times

3. Lower storage cost

4. Reduction in labor

5. Reduction in material handling

6. Flexible production system to meet customer‟s specific requirements.

Conventional high volume production facilities such as automatic equipment and

transfer lines do not fulfill these requirements. FMS or FMC can fulfill all the above. In

FMS functions have been already automated through the use of CNC and PLC. Monitoring

and process correction facilities through appropriate sensors are also part of the system so

that operator intervention is kept to a bare minimum.

SUBSYSTEMS OF FMS:-

There are 3 major subsystems in FMS:

1. Computer controlled mfg equipments (NC-CNC machines tools).

2. Automated materials storage, transport and transfer system.

3. Manufacturing control system (tool and logistic control).

Some FMS may have additional subsystems. For example, in a machining

application there may also be systems for storing and retrieving tools, disposing of chips

and cutting fluids, washing and inspection of work piece.

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SCOPE:-

Although this was initially developed for machining applications, now it is been

used in a variety of other manufacturing applications, such as

1. Assembly of equipments.

2. Semiconductor component manufacture.

3. Plastic injection moulding.

4. Sheet metal fabrication.

5. Welding.

6. Textile machinery manufacture.

But the systems (FMS) have proved to be practical and economical for application

with the following characteristics.

1. Families of part with the similar geometric features and require similar types of

equipment and processes.

2. A moderate no of tools and process steps.

3. Low to medium quantities of parts.

4. Moderate precision requirements.

FMS COMPARE TO OTHER TYPES OF MANUFACTURING APPROACHES:-

1. One-off and low volume of production is normally carried out by conventional

general-purpose machine tools.

2. When the no of parts in a production run is more it is called batch production.

3. A batch production shop is best suited for very small quantities of many different types

of parts.

4. The varying nature of production makes the operator of a job shop less efficient than

an automated production line.

5. Since the job shop must be provided the greatest degree of flexibility. Most of its

operational is manual.

6. They are normally provided with CNC-general purpose machine tools.

7. Hard automation with dedicated equipment is best suited for production of very large

quantities of identical parts.

8. Production of automobile component in a transfer line falls under this category.

9. A large no of manufacturing and portion of mfg industry involves the intermediate

level of batch operations that lend themselves to the FMS approach.

10. FMS thus basically attempts to efficiently automate batch manufacturing – an

alternative that that fits in between the manual job shop and hard automation.

11. It involves intermediate level of flexibility and low/medium quantities.

12. The chart shows the effect of variety and volume on the manufacturing system-type.

TYPES OF FMS:-

Having considered the issue of flexibility and the different types of flexibility that

are exhibited by manufacturing systems, let us now consider the various types of FMSs.

Each FMS is designed for a specific application, that is, a specific family of parts and

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processes. Therefore, each FMS is custom engineered; each FMS is unique. Given-these

circumstances, one would expect to find a great variety of system designs to satisfy a wide

variety of application requirements.

Types of flexibility in Manufacturing. These concepts of flexibility are not limited

to flexible manufacturing systems. They apply to both manned and automated systems.

FLEXIBILITY TYPE DEFINITION DEPENDS ON

FACTORS SUCH AS

Machine flexibility Capability to adapt a given machine Setup or changeover

(Workstation) in the system to a wide time. Ease of machine

range of production operations and part reprogramming (ease

styles. The greater the range of with which part

operations and part styles, the greater programs can be

the machine flexibility. Downloaded to

Machines).

Tools storage capacity

Of machines. Sill and

Versatility of workers

In the system.

Production flexibility The range or universe of part styles. Machine flexibility of

That can be produced on the system. Individual stations.

Range of machine

Flexibilities of all

Stations in the system.

Mix flexibility Ability to change the product mix Similarity of parts in

While maintaining the same total the mix. Relative

Production quantity; that is, producing work content times

The same parts only in different of parts produced.

Proportions. Machine flexibility.

Product flexibility Ease with which design changes can How closely the new

Be accommodated quantity. Ease with part design matches

Which new products can be the existing part

Introduced. Family. Off line part

Program preparation

Machine flexibility.

Routing flexibility Capacity to produce parts through Similarity of parts in

Alternative workstation sequences in the mix. Similarity of

Response to equipment breakdowns, workstations.

Tool failures, and other Duplication of

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Interruptions at individual workstations. cross

Stations. Training of manual

Workers. Common

Tooling.

Volume flexibility Ability to economically produce parts Level of manual labor

In high and low total quantities of performing

Production, given the fixed investment production. Amount

In the system. Invested in capital

Equipment.

Expansion flexibility Ease with which the system can be Expense of adding

Expanded to increase total production workstations. Ease

Quantities. With which layout

Can be expanded.

Type of part handling

System used. Ease

With which properly

Trained workers can

Be added.

Flexible manufacturing systems can be distinguished according to the kinds of

operations they perform:

(1) Processing operations or

(2) Assembly operations. An FMS is usually designed to perform one or the other but

rarely both.

A difference that is applicable to machining systems is whether the system will

process rotational parts of no rotational parts. Flexible machining systems machining

systems with multiple stations that process rotations parts are much less common than

systems that process non rotational parts.

Two other ways to classify FMS are by:

(1) Number of machines and (2) level of flexibility.

TABLE Comparison of four criteria of flexibility in a manufacturing system and the

seven types.

FLEXIBILITY TESTS OF CRITERIA TYPE OF FLEXIBILITY

1. Part variety test. Can the process different part Machine flexibility

Styles in a non-batch mode? Production flexibility

2. Schedule change test. Can the system readily Mix flexibility

Accept changes in production schedule, change Volume flexibility

In either part mix of production Quantities? Expansion flexibility

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3. Error recovery test. Can the system recover Routing flexibility

Gracefully from equipment malfunctions and

Break downs, so that production is not

Completely disrupted?

4. New part test. Can new part designs be Product flexibility

introduced into the existing product mix

relative ease?

NUMBER OF MACHINES:-

Flexible manufacturing systems can be distinguished according to the number of

machines in the system. The following are typical categories:

1. Single machine cell (type I A)

2. Flexible manufacturing cell (usually type II A, sometimes type III A)

3. Flexible manufacturing system (usually type II A, sometimes type III A,)

[Figure 6.1: Features of the three categories of flexible cell and system]

1. A SINGLE MACHINE CELL:-

(SMC) consists of one CNC machining center combined with a parts storage system

for unattended operation (Section 14.2), as in Figure 16.2. Completed parts are periodically

unloaded from the parts storage unit, and raw workparts are loaded into it. The cell can be

designed to operate in either a batch mode or a flexible mode or in combinations of the two.

When operated in a batch mode, the machine processes parts of a single style in specified

lot sizes and is then‟ changed over to process a batch of the next part style. When operated

in a flexible mode, the system satisfies three of the four flexibility tests (Section 16.1.1). It

is capable of (1) processing different part styles, (2) responding to changes in production

schedule, and (4) accepting new part introductions. Criterion (3), error recovery, cannot be

satisfied because if the single machine breaks down, production stops.

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[Figure 6.2: Single machine cell consisting of one CNC machining center and parts

storage unit]

2. A FLEXIBLE MANUFACTURING CELL:-

(FMC) consists of two or three processing workstations (typically CNC machining

centers or turning centers) plus a part handling system. The part handling system is

connected to a load/unload station. In addition, the handling system usually includes a

limited parts storage capacity. One possible FMC is illustrated in Figure 16.3. A flexible

manufacturing cell satisfies the four flexibility tests discussed previously. A flexible

manufacturing system (FMS) has four or more processing workstations connected

mechanically by a common part handling system and electronically by a distributed

computer system. Thus, an important distinction between an FMS and an FMC is the

number of machines: an FMC has two or three machines, while an FMS has four or more.2

A second difference is that the FMS generally includes non processing workstations that

support production but do not directly participate in it. These other stations include

part/pallet washing stations, coordinate measuring machines, and so on. A third difference

is that the computer control system of an FMS is generally larger and more sophisticated,

often including functions not always found in a cell, such as diagnostics and tool

monitoring. These additional functions are needed more in an FMS than in an FMC because

the FMS is more complex. Some of the distinguishing characteristics of the three categories

of flexible manufacturing cells and systems are summarized in Figure 16.4. Table 16.3

compares the three systems in terms of the four flexibility tests.

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[Figure 6.3: Flexible manufacturing cell consisting of three CNC machining center]

LEVEL OF FLEXIBILITY:-

Another classification of FMS is according to the level of flexibility designed into

the system. This method of classification can be applied to systems with any number of

workstation, but its applications seem most common with FMC and FMS. Two categories

are distinguished here:

Dedicated FMS

Random-order FMS

We have defined the dividing line that separates an FMS from an FMC to be

four machines. It should be noted that not all practitioners would agree with that

dividing line: some might prefer a higher value while a few would prefer a lower

number. Also, the distinction between cell and system seems to apply only to flexible

manufacturing systems that are automated., the manned counterparts of these systems

discussed in the previous chapter are always referred to as cells no matter how many

workstations are included.

DEDICATED FMS:-

A dedicated FMS is designed to produce a limited variety of p a r t s t y le s , a nd

t h e c o m plate universe of parts to be made on the system is known in advance. The term

special manufacturing system has also been used in reference to this FMS type .The part

family is likely to be based on product commonality rather than geometric similarity. The

product design is considered stable, and so the system can be designed with a certain

amount of process specialization to make the operations more efficient. Instead of using

general-purpose machines, the machines can be designed for the specific processes required

to make the limited part family, thus increasing the production rate of the system. In some

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instances, the machine sequence may be identical or nearly identical for all parts processed,

and so a transfer line may be appropriate, in which the workstations possess the necessary

flexibility to process the different parts in the mix.

[Figure 6.4: Comparison of dedicated and random order FMS types]

A RANDOM-ORDER FMS:-

Is more appropriate when the part family is large, there are substantial variations in

part configurations, there will be new part designs introduced into the system and

engineering changes in parts currently produced, and the production schedule is subject to

change. From day-to-day. To accommodate these variations, the random-order FMS must

be more flexible than the dedicated FMS. It is equipped with general-purpose machines to

deal with the variations in product and is capable of processing parts in various sequences

(random-order). A more sophisticated computer control system is required for this FMS

type. We see in these two system types the trade-off between flexibility and productivity.

The dedicated FMS is less flexible but more capable of higher production rates. The ran-

dom-order FMS is more flexible but at the price of lower production rates. A comparison of

the features of these two FMS types is presented in Figure 16.5. Table 16.4 presents a com-

parison of the dedicated FMS and random-order FMS in terms of the four flexibility tests.

FMS COMPONENTS:-

As indicated in our definition, there are several basic components of an FMS: (1)

workstations, (2) material handling and storage system, and (3) computer control system. In

addition, even though an FMS is highly automated, (4) people are required to manage and

system. We discuss t he s e fo u r FMS components in this section.

TABLE Flexibility Criteria Applied to Dedicated FMS and Random Order

FMS

System Type Flexibility Criteria (Tests of Flexibility)

1. Part variety 2. Schedule change 3. Error recovery 4. New part

Dedicated Limited. All Limited changes can Limited by No, new part

FMS parts known be tolerated. Sequential introductions

in advance. Processes. Difficult.

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Random Yes, Sub- Frequent and Machine Yes, system

Order stantial part significant redundancy designed for new

FMS variations changes possible. Minimizes part introduction.

possible. Effect of

Machine

Breakdowns.

WORKSTATION:-

The processing or assembly equipment used in an FMS depends on the type of work

accomplished by the system. In a system designed for machining operations, the principles

types of processing station are CNC machine tools. However, the FMS concept is also

applicable to various other processes as well. Following are the types of workstations

typically found in an FMS.

LOAD /UNLOAD STATIONS:-

The load / unload station is the physical interface between the FMS and the rest of

the factory. Raw work parts enter the system at this point and finished parts exit the system

from here. Loading and unloading can be accomplished either manually or by automated

handling systems. Manual loading and unloading is prevalent in most FMSs today. The

load/ unload station should be ergonomically designed to permit convenient and safe

movement of work parts. For parts that are too heavy to lift by the operator, mechanized

cranes and other handling devices are installed to assist the operator. A certain level o f

cleanliness must be maintained at the workplace and air hoses or other. Washing facilities

are often required to flush away chips and ensure clean mounting and locating points. The

station is often raised slightly above floor level using an open-grid platform to permit

chips and cutting fluid to drop through the openings for subsequent recycling or disposal.

The load/unload station should include a data entry unit and monitor for communi-

cation between the operator and the computer system. Instructions must be given to the

operator regarding which part to load onto the next pallet to adhere to the production

schedule. In cases when different pallets are required for different parts, the correct pallet

must be supplied to the station. In cases where modular fixturing is used, the correct fix-

ture must be specified, and the required components and tools must be available at the

workstation to build it. When the part loading procedure has been completed, the handling

system must proceed to launch the pallet into the system; however, the handling system

must be prevented from moving the pallet while the operator is still working. All of these

circumstances require communication between the computer system and the operator at

the load/unload station.

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MACHINING STATIONS:-

The most common applications of FMSs are machining operations. The

workstations used in these systems are therefore predominantly CNC machine tools. Most

common is the CNC machining center (Section (14.3.3_: in particular, the horizontal

machining center. CNC machining centers possess features that make them compatible

with the FMS, including automatic tool changing and tool storage, use of palletized work

parts, CNC, and capacity for distributed numerical control (DNC) (Section 6.3). Ma-

chining centers can be ordered with automatic pallet changers that can be readily

interfaced with the FMS part handling system. Machining centers are generally used for

non rotational parts. For rotational parts, turning centers are used; and for parts that are

mostly rotational but require multi tooth rotational cutters (milling and drilling), mill-turn

centers can be used.

In some machining systems, the types of operations performed are concentrated in

a certain category, such as milling or turning. For milling, special milling machine

modules can be used to achieve higher production levels than a machining center is

capable of. The milling module can be vertical spindle, horizontal spindle, or multiple

spindles. For turning operations, special turning modules can be designed for the FMS. In

conventional turning, the work piece is rotated against a tool that is held in the machine

and fed in a direction parallel to the axis of work rotation. Parts made on most FMSs are

usually non rotational; however, they may require some turning in their process sequence.

For these cases, the parts are held in a pallet fixture throughout processing on the FMS.

And a turning module is designed to rotate the single point tool around the work.

OTHER PROCESSING STATIONS:-

The FMS concept has been applied to other processing operations in addition to

machining. One such application is sheet metal fabrication processes. The processing

workstations consist of press working operations, such as punching, shearing. And certain

bending and forming processes. Also, flexible systems are being developed to automate

the forging process [41]. Forging is traditionally a very labor-intensive operation. The

workstations in the system consist principally of a heating furnace, a forging press, and a

trimming station.

ASSEMBLY:-

Some FMSs are designed to perform assembly operations. Flexible automated

assembly systems are being developed to replace manual labor in the assembly of

products typically made in batches. Industrial robots are often used as the automated

workstations in these flexible assembly systems. They can be programmed to perform tasks

with variations in sequence and motion pattern to accommodate the different product styles

assembled in the system. Other examples of flexible assembly workstations are the

programmable component placement machines widely used in electronics assembly.

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OTHER STATIONS AND EQUIPMENT:-

Inspection can be incorporated into an FMS, either by including an inspection

operation at a processing workstation or by including a station specifically designed for

inspection. Coordinate measuring machines special inspection probes that can be used in a

machine tool spindle and machine vision are three possible technologies for performing

inspection on an FMS. Inspection has been found to be particularly important in flexible

assembly systems to ensure that components have been properly added at the workstations.

In addition to the above, other operations and functions are often accomplished on

an FMS. These include stations for cleaning parts and/or pallet fixtures, central coolant de-

livery systems for the entire FMS, and centralized chip removal systems often installed

below floor level.

MATERIAL HANDLING AND STORAGE SYSTEM:-

The second major component of an FMS is its material handling and storage

system. In this subsection, we discuss the functions of the handling system, material

handling equipment typically used in an FMS, and types of FMS layout.

FUNCTIONS OF THE HANDLING SYSTEM:-

The material handling and storage system in an FMS performs the following

functions:

• Random, independent movement of work parts between stations. This means that parts

must be capable of moving from any one machine in the system to any other machine, to

provide various routing alternatives for the different parts and to make machine

substitutions when certain stations are busy.

• Handle a variety of work part configurations. For prismatic parts, this is usually

accomplished by using modular pallet fixtures in the handling system. The fixture is lo-

cated on the top face of the pallet and is designed to accommodate different part

configurations by means of common components, quick-change features, and other

devices that permit a rapid build-up of the fixture for a given part. The base of the pallet is

designed for the material handling system. For rotational parts, industrial robots are often

used to load and unload the turning machines and to move parts between stations.

• Temporary storage. The number of parts in the FMS will typically exceed the number of

parts actually being processed at any moment. Thus, each station has a small queue of

parts waiting to be processed, which helps to increase machine utilization.

• Convenient access for loading and unloading work parts. The handling system must

include locations for load/unload stations.

• Compatible with computer control. The handling system must be capable of being

controlled directly by the computer system to direct it to the various workstations,

load/unload stations, and storage areas.

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MATERIAL HANDLING EQUIPMENT:-

The types of material handling systems used to transfer parts between stations in

an FMS include a variety of conventional material transport equipment in-line transfer

mechanisms, and industrial robots. The material handling function in an FMS is often

shared between two systems: (1) a primary handling system and (2) a secondary handling

system.

The primary handling system establishes the basic layout of the FMS and is

responsible for moving work parts between stations in the system. The types of material

handling equipment typically utilized for FMS layouts are summarized in

The secondary handling system consists of transfer devices, automatic pallet

changers, and similar mechanisms located at the workstations in the FMS. The function of

the secondary handling system is to transfer work from the primary system to the machine

tool or other processing station and to position the parts with sufficient accuracy and

repeatability to perform the processing or assembly operation. Other purposes served by

the secondary handling system include:

(1) Reorientation of the work part if necessary to present the surface that is to be

processed and

(2) Buffer storage of parts to minimize work change time and maximize station

utilization. In some FMS installations, the positioning and registration requirements

at the individual workstations are satisfied by the primary work handling system. In

these cases, the secondary handling system is not included.

The primary handling system is sometimes supported by an automated storage sys-

tem (Section 11.4). An example of storage in an FMS is illustrated in Figure 16.6. The

FMS is integrated with an automated storage/retrieval system (AS/RS), and the S/R

machine serves the work handling function for the workstations as well as delivering parts

to and from the storage racks.

FMS LAYOUT CONFIGURATIONS:-

The material handling system establishes the FMS layout. Most layout

configurations found in today's FMSs can be divided into five categories: (1) in-line

layout, (2) loop layout, (3) ladder layout, (4) open field layout, and (5) robot-centered

cell.

In the in-line layout, the machines and handling system are arranged in a straight

line, as illustrated in Figures 6.5 and 6.6. In its simplest form, the parts progress from one

workstation to the next in a well-defined sequence, with work always moves in one

direction and no back flow, as in Figure 6.6. The operation of this type of system is sim-

ilar to a transfer line except that a variety of work parts are processed in the system.

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[Figure 6.5: Flexible manufacturing system]

[Figure 6.6: Flexible manufacturing system lay out]

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COMPUTER CONTROL SYSTEM:-

The FMS includes a distributed computer system that is interfaced to the

workstations material handling system, and other hardware components. A typical FMS

computer system consists of a central computer and microcomputers controlling the

individual machine and other components. The central computer coordinates the activities

of the component, to achieve smooth overall operation of the system. Functions performed

by the FMS computer control system can be grouped into the following categories:

1. WORKSTATION CONTROL:-

In a fully automated FMS, the individual processing or assembly stations generally

operate under some form of computer control. For a machining system, CNC is used to

control the individual machine tools.

2. DISTRIBUTION OF CONTROL INSTRUCTIONS TO WORKSTATIONS:-

Some form of central intelligence is also required to coordinate the processing at

individual stations. In a machining FMS, part programs must be downloaded to machines

and DNC is used for this purpose. The DNC system stores the programs, allows submission

of new programs and editing of existing programs as needed, and performs other DNC

functions.

3. PRODUCTION CONTROL:-

The part mix and rate at which the various parts are launched into the system must

be managed. Input data required for production control includes desired daily production

rates per part, numbers of raw workparts available, and number of applicable pallets.' The

production control function is accomplished by routing an applicable pallet to the

load/unload area and providing instructions to the operator for loading the desired .work

part.

4. TRAFFIC CONTROL:-

This refers to the management of the primary material handling system that moves

work parts between stations. Traffic control is accomplished by actuating switches at

branches and merging points, stopping parts at machine tool transfer locations, and moving

pallets to load/unload stations.

5. SHUTTLE CONTROL:-

This control function is concerned with the operation and control of the secondary

handling system at each workstation. Each shuttle must be coordinated with the primary

handling system and synchronized with the operation of the machine tool it serves. 'The

term applicable pallet refers to a pallet that is fixture to accept a workpart of the desired type.

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6. WORK PIECE MONITORING:-

The computer must monitor the status of each cart and/or pallet in the primary and

secondary handling systems as well as the status of each of the various work piece types.

7. TOOL CONTROL:-

In a machining system, cutting tools are required. Tool control is concerned with

managing two aspects of the cutting tools:

TOOL LOCATION:-

This involves keeping track of the cutting tools at each workstation. If one or more

tools required to process a particular workpiece is not present at the station that is

specified in the part's routing, the too (control subsystem takes one or both of the

following actions: (a) determines whether an alternative workstation that has the required

tool is available and/or (b) notifies the operator responsible for tooling in the system that

the tool storage unit at the station must be loaded with the required cutter (s).

TOOL LIFE MONITORING:-

In this aspect of tool control, a tool life is specified to use computer for each cutting

tool in the FMS. A record of the machining time usage is maintained for each of the tools,

and when the cumulative machining time reaches the specified life of the tool, the operator

is notified that a tool replacement is needed.

8. PERFORMANCE MONITORING AND REPORTING:-

The computer control system is programmed to collect data on the operation and

performance of the FMS. This data is periodically summarized, and reports are prepared for

management on system performance. Some of the important reports that indicate FMS

performance are listed in Table 16.6.

9. DIAGNOSTICS:-

This function is available to a greater or lesser degree on many manufacturing

systems to indicate the probable source of the problem when a malfunction occurs. It can

also be used to plan preventive maintenance in the system and to identify impending

failures. The purpose of the diagnostics function is to reduce breakdowns and downtime

and increase availability of the system.

HUMAN RESOURCES:-

One additional component in the FMS is human labor. Humans are needed to

manage the operations of the FMS. Functions typically performed by humans include:

a. Loading raw work parts into the system,

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b. Unloading finished parts (or assemblies) from the system,

c. Changing and setting tools,

d. Equipment maintenance and repair,

e. NC part programming in a machining system,

f. Programming and operating the computer system, and

g. Overall management of the system.

FMS BENEFITS:-

A number of benefits can be expected in successful FMS applications. The principle

benefits are the following:

1. INCREASED MACHINE UTILIZATION:-

FMSs achieve a higher average utilization than machines in a conventional batch

production machine shop. Reasons for this include 24 hr/day operation, (2) automatic tool

changing at machine tools, (3) automatic pallet changing at workstations, (4) queues of

parts at stations, and (5) dynamic scheduling of production that takes into account

irregularities from normal operations It should be possible to approach 80-90% asset

utilization by implementing FMS technology.

2. FEWER MACHINES REQUIRED:-

Because of higher machine utilization, fewer machines are required.

3. REDUCTION IN FACTORY FLOOR SPACE REQUIRED:-

Compared with a job shop of equivalent capacity, an FMS generally requires less

floor area. Reductions in floor space requirements are estimated to be 40-50% [23].

4. GREATER RESPONSIVENESS TO CHANGE:-

An FMS improves response capability to part design changes, introduction of new

parts, changes in production schedule and product mix, machine breakdowns, and cutting

tool failures. Adjustments can be made in the production schedule from one day to the

next to respond to rush orders and special customer requests.

5. REDUCED INVENTORY REQUIREMENTS:-

Because different parts are processed together rather than separately in batches,

work-in-process (WIP) is less than in a batch production mode. The inventory of starting

and finished parts can be reduced as well. Inventory reductions of 60-80% are estimated

[23].

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6. LOWER MANUFACTURING LEAD TIMES:-

Closely correlated with reduced WIP is the time spent in process by the parts. This

means faster customer deliveries.

7. REDUCED DIRECT LABOR REQUIREMENTS AND HIGHER LABOR

PRODUCTIVITY:-

Higher production rates and lower reliance on direct labor translate to greater

productivity per labor hour with an FMS than with conventional production methods.

Labor savings of 30-50% are estimated [23].

8. OPPORTUNITY FOR UNATTENDED PRODUCTION:-

The high level of automation in an FMS allows it to operate for extended periods

of time without human attention. In the most optimistic scenario, parts and tools are

loaded into the system at the end of the day shift, and the FMS continues to operate

throughout the night so that the finished parts can be unloaded the next morning.

FMS APPLICATIONS:-

The concept of flexible automation is applicable to a variety of manufacturing

operations. In this section, some of the important FMS applications are reviewed. FMS

technology is most widely applied in machining operations. Other applications include

sheet metal press working, forging, and assembly. Here some of the applications are

examined using case study examples to illustrate.

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EXPERIMENT.NO: 7

AIM: - TO STUDY ABOUT LINE OF BALANCE

HISTROY:-

- LOB was devised by the members of a group headed by George E. Fouch. During 1941,

the

Goodyear Tire & Rubber Company monitored production with LOB.

- It was successfully applied to the production planning and scheduling of the huge Navy

mobilization program of World War-II. LOB proved to be a valuable tool for expediting

production visibility during the Korean hostilities. During this period, defense suppliers

used LOB.

- LOB application has been further expanded, making it suitable now across a whole

spectrum of activities ranging from research and development through job shop and

process

flow operations.

- Specific forms and reports will be found to differ in detail, but the basic pattern and

symbologies are quite uniform throughout industry.

DEFINATION:-

The "Line of Balance" itself is a graphic device that enables a manager to see at

single glances which of many activities comprising a complex operation are "in balance" -

i.e., whether those which should have been completed at the time of the review actually are

completed and whether any activities scheduled for future completion are lagging behind

schedule.

OBJECTIVES (MEASURING TOOLS) OF LOB:-

1. Comparing actual progress with a formal objective plan.

2. Examining only the deviations from established plans, and gauging their degree of

severity

with respect to the remainder of the project.

3. Receiving timely information concerning trouble areas and indicating areas where

appropriate corrective action is required.

4. Forecasting future performance.

STAGES OF LOB:-

- LOB techniques consist of five main stages, all utilizing graphic aids,

1. A graphical representation of the delivery objective.

2. A chart of production programme showing the sequence and duration of all activities

required to produce a product.

3. A progress chart of the current status of component completion.

4. A line of balance drawn to show the relationship of component progress to the output

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needed to meet the delivery schedule.

5. Analysis of progress.

(1) OBJECTIVE CAHRT:-

The objective chart shows the expected schedule of products and the actual

completion rate.

- A fall in actual delivery line below the scheduled delivery line gives signal about

unsatisfactory progress.

[Figure 7.1: Objective chart]

(2) PROGRESS PLAN:-

A chart of the operations to complete one unit of the finished product is called the

program plan.

- In program plan various operation involved in the production process are reviewed and

listed along with lead-time.

- Each major raw of activities is associated with one of the final assembly. For convenience

the time scale runs from right to the left and final completion date is taken as zero. The

plane shows that items Y & Z must be combined t operation 10, two days before

completion

of final assembly. Item Z prior to this combination undergoes one conversion operation

(Operation no.6), which must be finished five days before final completion. Purchase of.

material [operation 5] for item Z must be completed by 6 days before final completion of

the

product. The item with the largest lead-time is 10 days i.e. Y.

- The completed chart serves as reference to the amount of lead-time by which each event

must precede final completion. Event must be completed by their respective lead times to

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maintain anticipated output (to meet delivery dates.)

[Figure 7.2: Program plan]

(3) PROGRESS CHART:-

Progress chart shows the number of items finished at each of the critical or

important operation at a given time.

- Let us assume that the review date is week no. 5 in fig.2 by which according to objective

chart, 50 items should have been finished i.e. 50 items must have passed the last operation

11, fig.7.3 of the program plan. The number of items that have completed this and each of

the other operation can be obtained simply by checking inventory levels.

The results can then be depicted by means of histogram. Fig.3 shows the progress

chart at week no.5.

(4) LINE OF BALANCE:-

The information given in progress chart Fig.7.3 is then used to compare the actual

progress with planned progress. For this a line is constructed on the progress chart, which

shows the requiste number of items, which should have been completed at each operation at

the time of review.

- The line of balance can be constructed analytically or graphically. The LOB shows the

total

number of items which should haven been completed at each operation.

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[Figure 7.3: Progress chart]

- Since a cumulative completion of 50 items is required for the 5th week a total number of

50

items must have completed operation 11 by this date.

- Operation 9 & 10 has a lead-time of two-week no.5. From the objective chart the delivery

for week no. 5 plus two days at 55 units (assuming 5 working days per week). The longest

lead time operation 1 is 10 days i.e. at week no.5 sufficient items to satisfy the delivery

requirements for week no. 5 plus 10 days i.e. 77 units should have been completed.

(5) ANALYSIS OF PROGRESS:-

For comparing the required progress it is again convenient to work backwards,

beginning with the last operation (11) from fig.3 it is clear that the requisite number of

completed items have been delivered to customer (operation 10=50), affect which is

reflected by the actual performance line on the object chart.

ADVANTAGES:-

1. Like network analysis (PERT, CPM etc) it planning discipline which in it self-useful.

2. It is a simple but powerful producer, which relies on several assumptions.

APPLICATION:-

1. Production of aircrafts.

2. Production of missiles.

3. Production of heavy machineries/equipments

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4. Production of special equipments/machineries

APPLICATION TO PRODUCTION (Case study):-

STANDARD SYMBOLS:-

All LOB chart use standard symbols, as shown in the lower right hand corner of

Exhibit 1. They identify the "sensors" (milestones), i.e., readily identifiable stages of

development or control point in the process designating completion of specific activities or

clusters of activities.

Exhibit 1 is a simplified example of a LOB Chart for a hypothetical fabrication and

assembly operation and demonstrates the original application in monitoring and controlling

production.

The finished LOB chart displays first, the OBJECTIVE (the required delivery

schedule), as shown in the upper left hand portion. Second, there is a clearly defined PLAN

for meeting that objective, indicating interrelationships, and how each part of component

fits into the assembly process, as well as the exact point in the cycle when each one is

required to be available. This is shown in the graphing of sensors, using standard symbols,

in the lower half of the chart. The bottom scale is the number of working periods (in this

case, the measure is in days), counting backwards from total completion, when each

component must be finished.

Third, there is an appraisal of the progress that has been achieved, given by the

vertical bars in the PROGRESS chart in the upper right hand portion. Finally, also in the

upper right hand portion, there is the LINE OF BALANCE, (i.e., a measure of the level of

progress that must have been reached if the objective is to be met on schedule, according to

the established plan). These four basic elements are vital ingredients of any effective

management system. Together they will provide for the continuous exercise of authority

and create a balanced and integrated operation out of a large number of individual and

uncoordinated transactions.

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[Exhibit 1]

The Objective curve is a plot of schedule cumulative deliveries against calendar

dates. In this instance, the curve tells us that a total of ninety units are scheduled for

delivery between November 1 and June 30. The dotted curve indicates that actual deliveries

have fallen below the required number, reaching only thirty-eight units by May 10, whereas

forty-eight had been planned.

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The Operating (manufacturing) Plan is represented by the series of interconnecting

horizontal lines, seen in the lower portion of the Line of Balance Chart. Along these lines

are the sensors indicating identifiable stages of development and control points. These

control point are numbered consecutively from left to right across the schematic diagram,

and from top to bottom wherever two or more points have a common position along the

horizontal axis. As will be seen later, each of these control sensors is keyed by a

corresponding number to a bar graph in the Progress portion of the LOB chart. The

Operation Plan illustrated has an established cycle of twenty-four days per unit. It indicates

the manner in which the several types and kinds of parts and components are joined to form

the completed product.

To restrict the number of sensor points to a minimum (no more than fifty), certain

conventions have been introduced. One convention is to develop a separate chart for each of

two or more categories of parts (such as, purchased, company made, major components,

customer furnished parts, etc.). In any case, there always remains the requirement for

summary of the whole to indicate the overall program state. A Summary Chart generally is

made by selecting key control points from each of the supporting charts, and having each

such point represent a number of subordinate sensors.

A similar device frequently is adopted in the treatment of complex products consisting of a

large number of parts. This expedient calls for each sensor to represent an association of

parts (for example, a so called "family group" of items on an indented parts list). Under

such conditions the symbol should be positioned for the earliest required part. All other

related data (such as stock status) should be representative of the least favorable condition

obtaining within the particular family group at the time of the survey.

The next step in our example is to cause a visual combination of the data displayed in the

Objective and the Plan portions of the chart. This will be used to establish a gauge for

measuring the performance requirements that will be necessary to meet the prescribed

delivery goal under operating conditions established by the Manufacturing Plan. This

combination of elements is known as the LINE OF BALANCE, the feature that gives its

name to the technique.

Deriving the Line of Balance Referring to Exhibit 1, note that the date of the progress

review is May 10. This now becomes the date for all reference purposes. The delivery

requirements at any time will be found by erecting a perpendicular at the point

corresponding to the date in question, and extending it to intersect the cumulative delivery

curve. The value of the ordinate at that point represents the required TOTAL DELIVERIES

for that time. In the case illustrated, the curve shows that by May 10 a total of 48 units

should have been shipped. In the Line of Balance, the 48 units relate to sensors 24 and 25,

the events that take place at the time of delivery.

For CURRENT needs to insure FUTURE deliveries, consider sensors Numbers 1 and 2.

These actions indicate initiation of the manufacturing cycle and are slated for

accomplishment 24 days prior to delivery of the finished unit. On May 10, we must have

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completed not only the 48 end items sets of items 1 and 2 required for delivery on that date,

but must also have completed an additional quantity sufficient to meet the shipping needs

24 working days later. The precise level of this requirement can be found by erecting a

perpendicular at the calendar date that is 24 working days after May 10, that is, June 13.

The cumulative delivery curve at that point calls for 78 finished units, showing that a total

of 78 end item sets of items 1 and 2 should have been completed (or have been available for

use on May 10). The Line of Balance is drawn at this level in the Progress Chart. Similarly,

sensor 3, which is slated for 23 days prior to the delivery date, must provide for

requirements for June 12, namely, 76 units, which is its Line of Balance.

Now, consider sensors numbers 4, 5, and 6, all of which are required 21 working days in

advance of shipment. The May 10 level of requirements for these items is represented by

the value of the ordinate at the point corresponding to June 10, 72 units. For sensor number

7, scheduled for accomplishment 18 working days in advance of shipment, a requirement

for 66 end item sets is shown by the Objective curve value for June 5.

By following the same principle of construction, requirement levels for all other elements

are established, culminating in a 48-unit delivery schedule by May 10, the date of the study,

and providing for planned future deliveries.

The end result is the characteristic step down contour of a Line of Balance. Properly

constructed, this invariably will step downward from a high point on the left to the level

indicated for cumulative deliveries on the date of the study. By comparing the Line of

Balance with the record of completed sensors of each item, management is afforded a

graphic portrayal of program status and an accurate forecast of shipping capability.

The vertical bars in the Progress chart are typical LOB representation of the progress being

made on a program. As was mentioned earlier, an identifying number to a bar graph display

keys each sensor in the Operating Plan. The length of this bar represents the number of end

item sets that have been completed or are available for use, as read off the vertical scale

used for the Objective curve. It will be noted that because of the manner in which the chart

was constructed, the bar graphs with the lowest numbers relate to the events that occur

earliest. This automatically points out the priority of corrective action. Also, because

progress is reported in terms of END ITEM SETS, the inventory count is translated into the

capability of delivery of finished units. That is to say, if the end product is a bicycle, the bar

graph for wheels will be on a length that is equivalent to the total number of wheels that

have been completed (or are available for use) divided by two. The results show how many

finished bicycles can be delivered out of the current stock level of wheels.

All the sensors that are behind schedule are indicated by bar graphs that fail to meet the

Line of Balance. The first of these is sensor number 8, complete fabrication of part "D".

Sensor number 8 is a "make" assembly which is manufactured relatively early in the factory

cycle. To the extent that supporting sensors 5 and 6 are on schedule, evidently some

problem exists in the fabrication process. The effects of this difficulty have been

transmitted throughout subsequent operations as may be seen by the bar graphs for 10, 15,

16, 18, 19, 21, 22, 23, 24, and 25. It may be concluded that the fault for shipping only 38

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instead of 48 units lies almost entirely with the failure to complete the required quantity of

part "D". The chart also reveals the presence of a problem area in the operation represented

by sensor 13 and 15. Even if the troubles with part D were cleared up, the deliveries would

be limited to only 51 units as shown by the height of bar graph 15.

This rudimentary example serves to illustrate the application of this technique to a simple

process of fabrication and assembly. Line of Balance can be applied to all other

manufacturing or production operations, whether they are job shop or flow shop. Although

more than some fifty years have elapsed since Line of Balance was first introduced, it is

still considered to be most effective for control of production.

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EXPERIMENT NO: 8

AIM: - WRITE-UP ON MATERIAL HANDLING

MEANING AND IMPROTANTCE OF MATEIRALS HANDLING:-

Materials handling is the primary activity of every manufacturing organization. It

has been estimated that at least 15 to 25% of the cost of the product is attributable to

materials handling activities and as such it warrants consideration in every branch of

manufacturing operation i.e. sitting the factory, planning the facilities, selecting the

manufacturing methods, mechanization, purchasing, receiving and storage, inspection,

warehousing and distribution of the final product.

Unlike many other operations, material handling adds to the cost of the product and

not to its value. It is therefore important first to eliminate or at least minimize the need for

handling and second to minimize the cost of handling. Most experts are of the opinion that

in majority of the company‟s materials handling costs can be cut to 50% of their current

level by employing scientific principles of material handling.

Materials handling may be defined as the art and science of movement, handling

and storage of materials during different stages of manufacturing considered as material

flow into, through and away from the plant. It is in fact, the technique of getting the right

goods safely to the right place at the right time and at the right cost.

Materials handling in an organization take place at various stages, such as the

following:

(a) Unloading at goods inwards stores.

(b) Loading on to an internal transport.

(c) Movement to stores for the purpose of storage.

(d) Movement from stores to place of use (first work station).

(e) Movement to a from work stations.

(f) Movement to and from inspection bays.

(g) Movement to and from assembly benches.

(h) Movement to and from finished goods stores.

(i) Movement from and to dispatch department

(k) Movement during packing

(l) Loading of packed materials on to a external transport

The above statements are the over simplification of the real complex situation. At

each stage materials are loaded, unloaded, positioned, repositioned, kept in/ taken out form

temporary area of storage, etc. Good materials handling practices require systematic

recording, critical review and improvement of all material handling activities to eliminate as

many movements as possible, and mechanization / simplification / modification of

remaining movements to reduce cost and improve efficiency.

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SYMPTOMS OF POOR MATEIRALS HANDLING:-

Some pointers to the poor materials handling system are:

1. Production losses due to delays in trucking, handling and supplying materials to the point

of use.

2. Long queues of vehicles at supply and dispatch points.

3. Congestion at receipt areas, inspection areas, production areas, preparation areas, and

dispatch areas.

4. Lack of activity in the operating areas specified for congestion above.

5. Frequent cases of material damages in handling.

6. Skilled labour performing work concerning movement, storage and handling of

materials.

7. Badly damaged floors and narrow passages.

8. Piling of work-in-process and materials at different locations.

9. Over crowded floor areas with blank overhead space.

10. Large number of unskilled contract labour to handle materials.

11. Frequent cases of material mix up and assembly being supplied wrong items.

12. Frequent breakdown of materials handling equipment.

13. Excessive loading / unloading time of jobs at the place of processing or testing.

14. Too frequent cases of rework and rejection due to handling defects.

15. Too frequent and too may aisles and passages blocked.

16. Difficulties in locating things when required.

17. Evidence of spillage, wastage, customers returns.

18. Bad housekeeping.

OBJECTIVES OF MATERIALS HANDLING:-

A well planned material handling system should achieve the following objectives:

(i) Speed and economy in movement of materials (i.e. minimization of processing time)

(ii) Minimization of cost of material handling.

(iii) Prevention of damages to materials.

(iv) Safety in material handling

(v) Minimization of fatigue and drudgery.

(vi) Improvement in productivity

(vii) Higher plant efficiency

(viii) Grater utilization of material handling equipment

(ix) Better house keeping

(x) Efficient store keeping

(xi) Lower investment in work in process.

ENGINEERING AND ECONOMIC FACTORS:-

Two important sets of factors to be considered in analyzing a material handling

problem are:

(i) Engineering factors and

(ii) Economic factors.

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1. ENGINEERING FACTORS:-

Engineering Factors can be further sub-grouped as under;

(a) Buildings and plant layout

(b) Manufacturing processes and equipment.

(c) Nature of materials and products to be handled.

(d) Materials handling equipments.

(a) BUILDING AND PLANT LAYOUT:-

This factor considers such features as:

(i) Processes and departments to be tied

(ii) Width of aisles

(iii) Location of columns

(iv) Ceiling heights

(v) No of floors

(vi) Load beaning strengths of the floors

(b) MANUFACTURING PROCESS AND EQUIPMENT:-

This factor considers features such as

(i) Production equipment

(ii) Method of production.

(iii) Sequence of operations.

(iv) Quantities of materials involved.

(c) NATURE OF MATERIALS AND PRODUCTS TO BE HANDLED:-

This factor analyses

(i) Nature of raw materials or parts handled (i.e. Large or small, singly or together, heavy or

light, symmetrical or non-symmetrical, rough or fragile etc.)

(ii) Quantities handled.

(iii) Continuous or intermittent flow

(iv) Distances over which transported.

(d) MATERIAL HANDLING EQUIPMENT FACTOR:-

(i) Kind of equipment suitable for the job (e.g. Trolleys, fork-lifts, trucks, conveyors,

overhead cranes etc.)

(ii) Capacity of the equipment

(iii) Hours of service per day.

(iv) Space required for operation

(v) Power requirements.

(vi) Ease of operation.

(vii) Speed of operation

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(viii) Auxiliary equipment required

(ix) Adaptability with the other equipment in use or contemplated.

2. ECONOMIC FACTORS:-

1. Initial cost of equipment

2. Cost of installation including rearrangement of alterations to the existing equipment.

3. Cost of maintenance and repairs

4. Cost of power

5. Cost of labour required to operate the equipment

6. Taxes and insurance

7. Interest on investment

8. Depreciation

9. License fees (e.g. Trucks)

10. Supervision costs

11. Salvage value

12. Saving due to reduction in number of men released for other work.

13. Saving due to expenses on equipment displaced.

14. Savings due to reduction in rework and rejection on account of improvement in

handling.

15. Savings due to increase in production as a direct consequence of changes in materials

handling system.

RELATIONSHIP BETWEEN PLANT LAYOUT AND MATERAILS

HANDLING:-

Plant layout and materials handling are closely inter-related. Only a good layout

cans causer least material handling and less costly material handling equipment.

Un- necessary materials movement damages the materials and causes loss of precious

man-hours in shifting materials. A layout designed to suit the manufacturing requirement

of the products reduces the materials handling to its minimum.

Productive time of workers can go workers can go waste if they have to frequently search

through the whole workshop for a particular tool or material. In order to utilize their time

more efficiently.

(i) All functional areas and aisles should be clearly identified and named.

(ii) Separate areas for raw materials, tools, work-in-process, inspection and finished goods

should be clearly defined.

A good layout, therefore, can avoid many a movements of men and materials.

Safe, smooth and speedy materials movement results when

(i) Bins, trolleys, racks and trays are utilized to keep materials instead of being place on

floors.

(ii) Products are properly packaged before its dispatch.

(iii) Conveyors, chutes, inclined planes and gravity feed bins are utilized to automatism

materials movement.

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Public utilities should be located in such a manner that the workmen do not need to travel

over long distances to attend to their personal needs. Due consideration must be given to

the location of the public utilities while preparing the layout of the plant.

Space cost money and is very costly too. Machines and equipment should be located in a

manner that there is no wastage of space and at the same time enough space should be

provided for future expansion. Lack of planning of space at the time of plant layout

causes congestion, wasted movements, damages to work-in-process and unnecessary

rework and rejects.

Alterations/ modifications in the layout at later date are usually expensive. In a good

layout, the widths of the aisles, heights of the ceilings, areas for the temporary storages,

etc. are planned in a manner that duplication of movements, back tracking of materials

and distortions in material flow do not take place while introducing economical material

handling equipment or expanding production activities at a later date.

Good plant layout thus helps building an efficient material handling system. It keeps

material handling at its minimum. Material movements are short, faster and economical.

Space requirements are considerably reduced. Congestion is avoided and damages to

materials are prevented. Machines and workers do not remain idle because of delay in

supplying the material. In general, the entire manufacturing activity is smooth. That is why

it is said that a good layout and minimum material handling are akin to each other.

PRINCIPLES OF MATERIAL HANDLING:-

PRINCIPLE 1: Planning Principle

All material handling should be result of a deliberate plan where the needs,

performance objectives, and functional specification of the proposed methods are

completely defined at the outset.

The plan should be developed in consultation between the planner(s) and all who will use

and benefit from the equipment to be employed.

Success in planning large-scale material handling projects generally requires a team

approach involving suppliers, consultants when appropriate, and end user specialists from

management, engineering computer and information systems, finance, and operations.

The plan should promote concurrent engineering of product, process design, process

layout, and material handling methods as opposed to independent and sequential design

practices.

The plan should reflect the strategic objectives of the organization as well as the more

immediate needs.

PRINCIPLE 2: Standardization principle

Material handling methods equipment controls, and software should be standardized

within the limits of achieving overall performance objectives and without sacrificing

needed flexibility, modularity, and throughput.

Standardization means less variety and customization in the methods and equipment

employed.

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Standardization applies to sizes of containers and other load for mining components as

well as operating procedures and equipment.

The planner should select methods and equipment that can perform a variety of tasks

under a variety of operating conditions and in anticipation of changing future

requirements.

Standardization, flexibility, and modularity must not be incompatible.

PRINCIPLE 3: Work Principle

Material handling work should be minimized without sacrificing productivity or the

level of service required of the operation.

The measure of material handling work is flow rate (volume, weight, or count per unit of

time) multiplied by distance moved.

Consider each pickup and set-down or placing material in and out of storage, as distinct

moves and components of the distance moved.

Simplifying processes by reducing, combining, shortening, or eliminating unnecessary

moves will reduce work.

Where possible, gravity should be used to move materials or to assist in their movement

while respecting consideration of safety and the potential for product damage.

The work principle applies universally, from mechanized material handling in a factory to

over-the-road trucking.

The Work Principle is implemented best by appropriate layout planning, locating the

production equipment into a physical arrangement corresponding to the flow of work.

This arrangement corresponding to the flow of work. This arrangement tends to minimize

the distances that must be traveled by the materials being processed.

PRINCIPLE 4: Ergonomic Principle

Human capabilities and limitations must be recognized and respected in the design

of material handling tasks and equipment to ensure safe and effective operations.

Ergonomics is the science that seeks to adapt work or working conditions to suit the

abilities of the worker.

The material handling workplace and the equipment must be designed so they are safe for

people.

The ergonomic principle embraces both physical and mental tasks.

Equipment should be selected that eliminates repetitive and strenuous manual labor and

that effectively interacts with human operators and users.

PRINCIPLE 5: Unit Load Principle

Unit loads shall be appropriately sized and configured in a way which achieves the

material flow and inventory objectives at each stage in the supply chain.

A unit load is one that can be stored or moved as single entity at one time, such as

appalled, container, or tote, regardless of the number of individual items that make up the

load.

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Less effort and work are required to collect and move many individual ideas as a single

load than to move many items one at a time.

Large unit loads are common both pre- and post manufacturing in the form of raw

materials and finished goods.

Smaller unit loads are consistent with manufacturing strategies that embrace operating

objectives such as flexibility, continuous flow and just in time delivery. Smaller unit loads

(as few as one item) yield less in process inventory and shorter item throughput times.

PRINCIPLE 6: Reduction in handling

The first principle of material handling is to minimize the material handling as far as

possible. The material should be moved as little as possible.

The selection of production machinery and the type of plant layout should be such

that material handling may be eliminated as far as possible.

Factors that are hat involve in reduction:

1. Process changes

2. Layout improvement

3. Increased size of units handled

4. Use of proper equipment.

PRINCIPLE 7: Reduction in time

Time is money. Time lost a means paying wages to the workers when they are not

doing productive work. Time lost reduces the rate of output and increase the un it overhead

cost. Therefore time of each move should be minimized.

Time is consumed principally in three things

1. Waiting

2. Loading and unloading

3. Travel time.

Waiting time may be reduced by proper scheduling, well organization of labor

forces, providing proper or sufficient facilities for loading, removing c9onjection in the

plant.

PRINCIPLE 8: Use of gravity

Wherever possible utilize gravity for assisting material movements as it is the

cheapest source of motive power

PRINCIPLE 9: Safety

Safe, standard, efficient, effective, appropriate and flexible material hand ling

equipment should be used.

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PRINCIPLE 10: Use of containers

Design containers, tailors, drums etc. to reduce the cost of hand ling and damage of

the material in transit

PRINCIPLE 11: Stand by facility

The provision of standby facilities should be made so that the sudden breakdown

may not stop the operation due to non-availability of materials.

PRINCIPLE 12: Periodical check up

The check up repairing and maintenance of the existing material handling

equipments should be made periodically

MATERIAL HANDLING DEVICES:-

Material handling devices are of three types.

1. LIFTING AND LOWERING DEVICES (VERTICAL MOVEMENTS):-

a. Block and tackle.

b. Hand and power winch

c. Hoists

d. Elevators.

e. Pillar crane.

f. Overhead crane.

2. TRANSPORTING DEVICES (HORIZONTAL DEVICES):-

a. Wheel barrows.

b. Hand and power trucks

c. Industrial narrow railways.

d. Tractors and tailors.

3. DEVICES WHICH LIFT AND TRANSPORT (COMBINATION DEVICES):-

a. Chutes.

b. Hoist with trolleys running on overhead rails

c. Fork loft trucks

d. Crain trucks

e. Different types of conveyors

f. Spiral chutes.

g. Spiral rollers

h. Cranes

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BLOCKS AND TACKLE:- [Figure 8.1: Block and tackle]

It is one of the oldest and simplest methods of lifting something through a vertical

distance it is still used by moving man and in hoisting machinery in two positions. It

depends in general on man power and gives only the mechanical advantage that is possible

for the various rope formations.

WINCHES:- [Figure 8.2: Winches]

They are frequently used in loading heavy equipment into ships, construction

equipment into building and in similar job.

HOISTS:- [Figure 8.3: Power hoist]

They may be fixed in one place, attach to Crain, mounted o0n monorails trolleys or

on a single rails. The simplest type is the chain hoist which is operated by hand the most

complicated forms of hoist are those which resembles elevators in every detail except that

no operator rides upon them.

ELEVATORS:- [Figure 8.5: Elevator (Hydraulic type)]

These are differentiated form hoist by the fact that the operator rides with the load.

There are many different types of drivers for search elevators, but in general electrical drive

is most common. Hydraulic e4levators are used only where it is dangerous to take the

chance of an electric spark, as in acetylene generator houses

PILLR CRANE:- [Figure 8.4: Pillar crane]

The pillar crane may be stationary type or mobile type. It is used for light duty and

for lifting loads up to 20 tones. All movements to the crane are provided by gearing and

electric motor drive.

OVERHEAD BRIDGE CRANE:- [Figure 8.6: Overhead bridge crane]

It has both transverse and longitudinal movements. The Crain hook thus moves in a

rectangular area can reach to any part of rectangular floor or yard. It is used in foundry,

power house, chemical plants, heavy fabrication industry, and steel industry.

HAND TRUCKS AND WHEEL BARROWS:- [Figure 8.9: Hand truck]

[Figure 8.10: Wheel Barrow]

The simplest transporting devices are wheel barrows and hand trucks. These are still

in used in number of small industries. This equipment involves a large amount of man

power for a relatively small load.

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The chief advantage of these equipment is its very low cost, its great flexibility and

its easy portability form one job to another industrial railways they are narrow gauge

railway roads. In general little use is made of such equipment because it requires a heavy

investment in the road, bed and track. They still found in metal working industry and in

mining activities, it is cheaper or more desirable to lay tracks than to pave the entire area.

TRACTORS AND TRAILERS:-

This is one of the most common met5hod of horizontal transportation for material

handling. This method is most flexible as tractors can be connected to different types of

trailers. Trailers can be disconnected form the tractors, left loaded and can be pieced up by

different tractors. It is one of the most imported methods of handling materials inside the

plant and from one building to another.

PIPE LINE:-

Pipeline and pumps are also used for horizontal transportation of commodities. Most

obvious among these is oil, which is pum-poed great distance through pipeline. Gas,

principally natural gas is also carried out through pipelines. Water is also carried.

SLIDES AND CHUTES:- [Figure 8.11: Spiral chute]

One of the simplest devices that have both vertical and horizontal motion is a slide

or chute it may be straight or spiral. Gravity is utilities to move materials down and if

desired, to change the position horizontally of the load. Chutes are common in railways and

airlines terminals for handling packages. They are used in departmental stores particularly

in spiral form to ship stock from reservoirs form the upper floor to the lower.

TRUCKS:-

The trucks are used to move the heavy materials over varying parts. They are either

manually operated or power operated. Industrial trucks are preferred

a. When materials are to be picked up and moved impertinently different routes

b. When material are of mixed size and weight

c. When it is possible to use unit load

d. When cross t4affic exist

CRANE TRUCKS:- [Figure 8.14: Crane Truck]

Mall crane trucks operate on the same principle as lift trucks. They are used for

materials that cannot be put on the skids, or is not available on the skid at the present time,

or is much heavy to handle with lift trucks. It moves quickly over smooth, even in hard

ground. It can be carried at will and to any place.

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CONVEYORS:-

That is a device which is moves materials in either horizontal or vertical direction

between two fixed points. They maybe fixed or portable conveyors, straight or circular

ones. The materials are feed to the conveyors from some other source sat the point of start;

they are carried by the conveyors to the point of destination. They are driven with the help

of power or without power.

TYPES OF CONVEYORS:-

a. ROLLER CONVEYOR:- [Figure 8.15: Roller Conveyor]

These are flat, circular or spiral. They consist of roller supported in frames over

which materials are allowed to move. They are driven to gravity. Generally materials

having flat bottoms are moved, other wise boxes or pallets are used.

b. BELT CONVEYOR:- [Figure 8.17: Belt Conveyor]

It consists of endless belt. It has poor driven pulley at one end which moves the belt

continuously. It may be flat or elevator with upward or downward flow of materials.

Generally the belt is made of rubbers, canvas, fabric, leather, or woven wires.

c. CHAIN CONVEYOR:- [Figure 8.18: Chain Conveyor]

It consists of overhead mounted endless chain. It is supported from the ceiling and

has affixed path to travel. It saves valuable floor space. The arrangement is such that the

lifting mechanism lowers down for loading and unloading of the product to be handled.

d. BUCKET CONVEYOR:- [Figure 8.20: Bucket Conveyor]

These are used to move the granular, powered or; liquid materials. The bucket may

be on a chain or belt mounted. The movement may be vertical or flat. The vertical

movement may be continuous where in buckets are hooked in a sequential circular manner,

or discrete where buckets are hooked for lifting.

e. SCREW CONVEYORS:- [Figure 8.19: Screw Conveyor]

These are used principally for transmitting materials in the form of powder or paste

with the application of rotating screw for example feeding pulveri8zed coal into the

furnace.

MATERIAL HANDLING SYSTEM EQUATION:-

Provides a means to identify opportunities for improvement, it gives us a framework

for identifying solutions to material handling problems. The what defines the type of

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materials moved, the where and when identify the place and time requirements, the how

and who point to the material handling methods. Leads us to

Materials + Moves + Methods = Recommended System

SCOPE OF MATERIAL HANDLING:-

a. MANUFACTURING:-

1. Raw materials receiving and shipping

2. Materials issue and distribution

3. Inter/intra departmental handling

4. Workplace material handling

5. In-process storage

6. Finished goods storage

7. Stock picking and order assembly

b. HOSPITALS:-

1. Patient handling

2. Staff personnel handling

3. Food handling

4. Garbage handling

5. Laundry handling

6. Medication handling

7. Patient records handling

c. AIRPORTS:-

1. Passenger handling

2. Flight crew handling

3. Baggage handling

4. Fuel handling

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5. Food handling (flight meals and terminal)

6. Air freight cargo handling

[Figure 8.1: Block and tackle] [Figure 8.2: Winches]

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[Figure 8.3: Power hoist] [Figure 8.4: Pillar crane]

[Figure 8.5: Elevator (Hydraulic type)]

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[Figure 8.6: Overhead bridge crane]

[Figure 8.7: Jib crane]

[Figure 8.8: Gantry crane] [Figure 8.9: Hand truck]

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[Figure 8.10: Wheel Barrow] [Figure 8.11: Spiral chute]

[Figure 8.12: Fork Lift Truck] [Figure 8.13: Lift Truck]

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[Figure 8.14: Crane Truck] [Figure 8.15: Roller Conveyor]

[Figure 8.16: Roller Spiral Conveyor] [Figure 8.17: Belt Conveyor]

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[Figure 8.18: Chain Conveyor] [Figure 8.19: Screw Conveyor]

[Figure 8.20: Bucket Conveyor] [Figure 8.22: Shelving for Loose or Boxed

Items]

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[Figure 8.21: Classification of Material Handling System]

[Figure 8.23: Fork Lift Truck]

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[Figure 8.24: Three Tonne Counter Balance Tuck] [Figure 8.25: Pallet Based

Stacker]

[Figure 8.26: Straddle Base Stacker] [Figure 8.27: Bin Handling Carts and

Trolleys]

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[Figure 8.28: Reach Trucks]

[Figure 8.29: Application of AGV]

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[Figure 8.30: Overhead Travelling Cranes]

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[Figure 8.31: Gantry Cranes]

[Figure 8.32: Power Pallet Truck] [Figure 8.33: Stand-on Powered

Pallet Truck]

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[Figure 8.34: Powered Pallet Tuck [Figure 8.35: Site-on Powered Pallet Tuck]

With Fold-up Stand-on Platform]

[Figure 8.36 Moving Pallet Loads in a Furniture Warehouse]

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[Figure 8.37: Rail-Mounted Order Pickers [Figure 8.38: Rail-Mounted Order

are Particularly Useful For Quick Pickers are Suitable for Goods

Convenient Retrieval from Shelving] Handled at low to Medium rates]

[Figure 8.39: Shelving for Storing [Figure 8.40: Spiral Chute]

Loose o Boxed Item]

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[Figure 8.41: Jib Cranes and Other Fixed Units]

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[Figure 8.42: Light Weight Goods

Spiral Chute made from Steel Wire]

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[Figure 8.43: Application of AVG]

[Figure 8.44: Overhead Conveyors]

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[Figure 8.45: Light Duty Lift with Mesh Shaft]

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[Figure 8.46: Chain Conveyors]

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[Figure 8.47: Slat Conveyors]

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[Figure 8.48: Load Carries (Pallets, Stillages, etc)]

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[Figure 8.49: Belt Conveyors]

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[Figure 8.50: Tray Conveyors]

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[Figure 8.51: Roller Conveyors]

[Figure 8.52: Classification by Load Carrying Components]

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EXPERIMENT.NO: 9

AIM: - WRITE-UP ON AUTOMATION IN MATERIAL HANDLING

EQUIPMENT

Material handling is an important outlook aspect of automation. The cost of material

handling is a significant portion of the total cost of production.

FUNCTION:-

The purpose of material handling in a factory is to move raw material, working

process, finished parts, tools and supplies from one location to another to facilitate the

overall operations of manufacturing.

The handling material must be performed safely, efficiently in a timely manner,

accurate and without damage to the materials.

The material handling function is also concerned with material storage and material

control.

The material control function is concerned with the identification of the various

materials in the handling system, their routings, and the scheduling of their moves.

WHY AUTOAMTED MATERIAL HANDLING SYSTEM REQUIRED:-

1. FOR SAFETY PURPOSE 2. LOW COST OF HANDLING 3. NO DAMAGE TO THE MATERIAL 4. ACCURATELY HANDLING 5. IDENTIFICATION OF THE VARIOUS MATERIALS IN THE HANDLING

SYSTEM

MATERIAL HANDLING EQUIPMENTS:-

Material handling equipment includes

1. Transport equipment

2. Storage system

3. Utilizing equipment

4. Identification and tracking

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MATERIAL TRANSPORT EQUIPMENT:-

INDUSTRIAL TRUCK:-

Industrial truck divided into two types: non powered and powered. Non-powered

trucks are platforms for containers with wheels that we push and pull by human power

industrial truck are steered by human worker.

[Figure 9.1: Powered trucks and non-powered trucks]

AUTOMATED GUIDED VEHICLE:-

AGVs are battery powered automatically steered vehicles that follow defined

pathways in the floor. AGVs are used to move unit loads between loads and unload stations

in the facility. Routing variations are possible meaning that different loads move between

different stations.

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[Figure 9.2: Automated guided vehichal]

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MONORAILS AND OTHER RAIL GUIDED VEHICLES:-

These are self-propelled vehicles that ride on a fixed rail system that is either or on

the floor or suspended from the ceiling. The vehicles operated independently and are

usually driven by electric motor.

[Figure 9.3:3-D Monorails]

CONVEYORS:-

[Figure 9.4: Conveyors]

Conveyors constitute a large family of material transport5 equipment that is

designed to move material over fixed paths, generally in large quantities or volumes.

CRANES AND HOISTS:-

These are handling devices for lifting or lowering and transporting material often as

very heavy loads. Hoists accomplish vertical lifting, both manually operated and power

types are available. Cranes provide horizontal travel and generally include one or more

hoists.

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[Figure 9.5: Cranes and hoists]

CONVEYOR SYSTEM:-

Conveyor system is used when materials must be in relatively large quantities

between specific locations over a fixed path.

ATTRIBUTES:-

1. They are generally mechanized and sometimes automated.

2. They are fixed in position to establish the paths.

3. They can either floor mounted or overhead.

4. They are almost always limited to one directional flow of materials.

5. They can be used for either delivery only or delivery plus storage items.

TYPES OF CONVEYORS:-

(1) ROLLER CONVEYOR:-

This is a very common form of conveyor system. The path consists of a series of

tubes that are perpendicular to the direction of travel.

- The rollers are contained in a fixed frame.

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- Flat pellets or tote pans carrying unit loads are moved forward as the roller rotate.

- Roller conveyors can be either powered or gravity type.

- The powered types are driven by general mechanism, belts and chains are common.

- The gravity types are arranged so that the pathway is along a downward slope sufficient

to overcome rolling friction.

- Roller conveyors can be used for delivering loads between manufacturing operations,

delivery to and from storage, and distribution application.

(2) SKATE WHEEL CONVEYORS:-

- These are similar in operations to the roller conveyors.

- Instead of rollers skate wheels rotating on shafts connected to the frame are used to roll

pellet or tote pan or other container along the pathway.

- Applications of conveyors are similar to those for roller conveyors, except that the loads

must generally be lighter.

(3) BELT CONVEYORS:-

- This type is available in two common forms; flat belts for pellets, parts or even contain

types of belt materials used through belts for bulk materials.

- Materials are placed on the belts surface and travel along the moving pathway.

- Belt is made into a continuous loop so that half of its length can be used for delivering

materials and the other half is return run.

- The belt is supported by frame that has rollers or either supports space every few feet.

(4) CHAIN CONVEYORS:-

- Chain conveyors are made of loops of endless chain in an over and under configuration

around powered sprockets at the end of the pathway.

- The load generally rides along the top of the chain; in some cases, a pusher projects up

between two parallel chains to push the load along a track rather than having the load

ride directly on the chain itself.

(5) SLAT CONVEYOR:-

- The slat conveyor uses individual platforms, called slats that are connected to a

continuously moving chain.

- Although its drive mechanism is the power chain it operates much like a belt conveyor.

- Loads are placed on the flat surface of the slats and are transported along with them.

(6) OVERHEAD TROLLEY CONVEYORS:-

- A trolley in material handling is a wheel carriage running on an overhead rail from

which loads can be suspended.

- A trolley conveyor consists of multiple trolleys usually equally spaced along the rail

system by means of an endless chain or cable.

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AUTOMATIC GUIDED VEHICLE SYSTEM:-

- It is a material handling system that uses independently operated, self-propelled

vehicles that are guided along defined pathways in the floor.

- The vehicles are powered by means of on board batteries that allow operation floor

several hours between recharging

- Sensors on the vehicles that can follow the guide wire or paint achieve guidance.

TYPES OF AGVs:-

1. DRIVERLESS TRAINS:-

- This type consists of a touring vehicle that pulls me or more trailers to form a train.

- It was the first type of AGVs to be introduced and is still popular.

- It is useful in application where heavy payloads must be moved large distance in

warehouse or factories with intermediate pick up and drop points along the route.

2. AGVs Pallet Trucks:-

- Automated guided pallet truck is used to move palletized loads along predetermined

routes.

- In the typical application the vehicle is backed into the loaded pallet by a human worker

who steers the trucks and uses its forks to elevate the load slightly.

- Then the worker drives the pallet truck to the guide path.

- Programs its destination and the vehicle precedes automatically to the destination for

unloading.

[Figure 9.6: AGVs pallet trucks]

3. AGVS UNIT LOAD CARRIERS:-

- This type of AGVs is used to move unit loads from one station to another station

- They are often equipped for automatic loading and unloading by means of powered

rollers, moving belts, mechanized lift platforms or other devices.

- Variations of the unit load carrier include light load AGVs and assembly live AGVs.

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- Light load AGVs is a relatively small vehicle with a corresponding light load capacity.

- Light load guided vehicles are designed to move small loads through plants of limited

size engaged in light mfg.

- The assembly line AGVs is designed to carry a partially completed of subassembly

through a sequence of assembly workstations to build the product.

APPLICATION OF AGVs:-

Automated guided pallet trucks are used to move palletized loads along

predetermined routes. The capacity of AGVs pallet truck ranges up to several thousand

kilograms and some trucks are capable of handling two pallets rather than are AGVs unit

load carries are used to move unit loads from one station to another station.

1. STORAGE AND DISTRIBUTION:-

Unit load carries and pallet truck are typically used in these applications, which

involve moment on material in unit loads.

2. ASSEMBLY LINE APPLICATION:-

Unit load carries and light lo9ad guided vehicles are used in these lines. In the usual

application the product rate is relatively low and there are several differently product

models made on the line each requiring a different processing time.

3. FLEXIBLE MANUFACTURING SYSTEM:-

In the typical operations, human workers in a staging area and the AGVs delivery

place starting work parts on to pallet fixtures the parts to the individual workstations in the

systems. AGVs provide a very stile material handling system complement the flexibility of

the FMS.

4. MISCELLANEOUS APPLICATIONS:-

AGVs used to office mail delivery and hospital material transport. Hospital guided

vehicles transports meal trays, linear medical and laboratory supplies, and other materials

between various departments in the building

VEHICLE GUIDANCE TECHNOLOGY:-

Three technologies that we used in commercial systems for vehicle guidance

1. Imbedded guide wires

2. Paint strips

3. Self guided vehicles

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IMBEDDED GUIDE WIRES:-

In the imbedded guide wire method electrical wires are placed in a small channel cut

into the surface of the floor. The channel is typically 3-12 mm wide and 13-26 mm deep.

After the guide wire is installed the channel is filled with cement to eliminate the

discontinuity in the floor surface.

The guide wire is connected to a frequency generator which units a low - voltage

low current signal with a frequency in the range 1-15 kHz, this include a magnetic fields

along the pathway that can be followed by sensors on-board each vehicle.

Two sensors are mounted on the vehicle on either side of the guide wire when the

vehicle is located such that the guide wire is directly between the two coils, he intensity of

the magnetic field measured by each cool will be equal.

If the vehicle strays to me side or the other or if he guide wire path changes

direction he the magnetic field intensity at the two sensors will be different this different is

used to control the steering motor, which makes the required changes in vehicle direction to

equating he two sensor signals, thereby tracking the guide wire.

PAINT STRIPS:-

- When paint strips are used to define the pathways, the vehicle uses on optical sensor

system capable of tracking the paint

- The strips can be taped sprayed or painted on the floor. One system uses a 1- in - wide

paint strip containing fluorescent particles that reflect on ultraviolet light source from

the vehicle.

- Paint strip guidance is useful in environments where electrical noise renders the guide

wire system unreliable or when the installation of guide wires in the floor surface is not

practical.

- On problem with this guidance method is that the paint strip deteriorates with time. it

must be kept clean and periodically repainted.

SELF - GUIDED VEHICLES:-

- SGVs represent the latest AGVs technology.

- SGVs operate without continuous defined pathways. They use a combination of dead

reckoning and be a cons located throughout the plant, which can be identified by on

board sensors.

- Movement of the vehicle along the outer is accomplished by computing the required no

of wheel rotations in a sequence of specified steering angles.

- The advantages of Self-guided vehicles technology over fixed pathways are its

flexibility. The SGV pathways are defined in software. Entering the required data into

the navigation computer can change the path network.

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AUTOMATED STORAGE EQUIPMENT:-

1. SHELVING AND BINS:-

– Steel shelving comes in standard width, depth and height to serve a variety of storage

requirements.

– Shelves can include bins which are container for loose item.

2. RACK SYSTEM:-

These are structure frame region to stock unit load vertically. Thus increases the

vertical storage efficiency compare to bulk storage.

3. BULK STORAGE:-

– This consists of simply storing material in generally open floor area, generally in pallet

or either in containers.

[Figure 9.7: Bulk storage]

4. DRAWER STORAGE:-

– This storage medium is more costly than previous one.

– But it is more convenient

– Finding item stored in shelve can be difficult if a self level is

too high or too low or too deep.

– Drawer component for this by pulling out to retrieve that entire container.

– Drawer containers generally use for tools and other small items.

5. AS\RS SYSTEMS:-

DEFINITION:-

A combination of equipment and controls which handles stores and retrieves

materials with precision, accuracy and speed under a defined degree of automation.

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AS/ RS Components:-

– Storage aisles with storage racks

– Storage and retrieval machines (one machine per aisle)

– One or more pickup and delivery stations

This system is available to deposit or redraw items in to end from the storage

compartment. There are two types basically.

1. AS\RS.

2. Carouser system.

* CAROUSER SYSTEM:-

– The system that rotates storage bins with respect to a stationary load or unload system.

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EXPERIMENT.NO: 10

AIM: - TO STUDY ABOUT SAFETY ENGINEERING

INTRODUCTION:-

Technological development is taking place at very fast rate in all the fields in the all

the fields like mechanical, metallurgical, chemical, electrical, and civil. These days every

man is surrounded by automobiles, trains, aeroplane, explosives, noise and air pollution etc.

that may cause accidents. The danger of life of human being is increasing with the

advancement of industrial safety was establishment or permanent disablement of the

employees and involves large amount of lows resulting from damage to property and

wasted man hours and machine hours. Now a day a serious attention is being paid to reduce

the rate of accident safety rules have been devised for each and every field to safe guard the

interest of society. Hazard control and accident prevention have been considered as a basic

needs. Health and safety are basic desire and instinct. We believe in concept of safety,

human protection and protection of nature. The benefits of accident prevention have been

well understood and accepted by industries throughout the world.

PROBLEM OF INDUSTRIAL ACCIDENTS:-

Accident may be defined as unforeseen, uncontrolled, undesirable and sudden

mishap, which may result in minor injuries, major injuries or death of the person involved,

loss of property and interruptions in activities or functions in industry.

The adverse effects of accident can be summarized as under:

1. EFFECT ON THE INDUSTRY OR OWNER:-

An accident can be very costly to the industry as well as to the employees. The costs

associated with accident can be classified as:

(i) Direct costs

(ii) Indirect costs.

2. DIRECT COST OF AN ACCIDENT:-

1. Compensation has to be paid to the worker for temporary or permanent disability caused

by accident.

2. Money paid of treatment and cure of workers disabled by on job accident.

3. Money value of damaged equipment and materials, expenses towards repairs,

replacement

of damaged machines and equipment.

3. INDIRECT COST OF ACCIDENT:-

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1. Cost of lost time of injured worker.

2. Cost of time lost by other employees who stop work?

3. Cost of time lost by foreman, supervisors, safety engineers or other executives

4. Cost of interruptions and delays in production due to accident.

5. Cost of lowered production due to substitute worker.

6. Cost of subsequent injuries that occurs in consequence of the excitement or weakened

morale due to original accident.

ACCIDENT CAUSES:-

1. Continued use of old, poorly maintained of unsafe equipment. This is generally

accompanied by failure to have regular plant safety and preventive of all production

facilities in accordance with a properly designed time schedule.

2. Unguarded or improper guarded machines or equipment, guards of improper height,

strength, mesh etc.

3. Unsafe process, mechanical, chemical, electrical, nuclear etc.

4. Unsafe design and construction of building structures etc.

5. Improper material handling system.

6. Improper plant layout.

ENVIRONMENTAL FACTORS:-

1. Temperature and humidity: Low temperature causes shivering. Too high temperature

causes headache and sweating, this also causes fatigue to the operator. Too high humidity

(As textile industry) may cause uncomforted, fatigue, drowsiness especially when the

atmosphere is too hot.

2. Defective and inadequate illumination: It causes glares, shadows, eyestrain etc.

Presence of dust fumes and smoke

3. Overly fatigued worker: Excess fatigue may arise out of work assignment that may tax

the

worker‟s physical and mental powers (excessive overtime, inadequate rest pauses).

4. Unsafely arranged, poorhouse keeping, congestion, blocked exits, bad plant layout or

arrangement of machines.

5. Harsh or dominating behavior of management or supervisors towards worker.

6. The type of leadership style adopted by the management in the organization.

HUMAN CAUSES:-

1. UNSAFE ACTS:-

Unsafe act may be defined as the deviation from the normal and correct procedure

or practice. It results in unnecessary exposure to hazards or conduct minimizing the degree

of safety. Any human action is manifestation of mental or psychological set up. Hence

unsafe act is relates to the psychological accepts of the workers. The following are unsafe

acts:

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1. Operating without authority.

2. Operating or working at unsafe speed.

3. Making safety devices inoperative.

4. Using unsafe equipment or using equipment unsafely.

5. Taking unsafe position or posture.

6. Unsafe loading, placing, mixing, combining etc.

7. Improper use of tools.

2. THE UNSAFE PERSONAL FACTORS:-

The unsafe personal factors are the mental or bodily characteristics which promote

unsafe acts. These are:

1. Improper attitude.

2. Ignorance, forgetfulness, carelessness, day dreaming etc.

3. Lack of knowledge and skill

4. Home environment.

5. Mental worries.

PRIME SOURCE OF ACCIDENTS:-

Accounting to psychologists:

1. Married workers meet with less accident in comparison to their unmarried colleagues.

Addict workers and those who are frustrated and fatigued exhibit higher rate of accident.

2. Employees working under stress along with a sense of insecurity meet more accidents as

compared to the normal employees.

3. Safety records are better in case of female workers as compared to their male

counterparts.

4. The frequency of accidents during the night shift is more as compared to day shift.

5. Rate and frequency of accidents is affected by the type of motivation and the leadership.

style adopted by the management.

6. Workers, who are trained, experienced and in the high age groups generally meet less

accident.

ACCIDENT CONTROL OR PREVENTION:-

Accident prevention involves removal or control of hazards. It is both sciences and

art. It represents above all other things, control of human performance, machine

performance and physical environment. „Control‟ here means prevention as well as

correction of unsafe actions and conditions. Accident prevention requires combination of

efforts using:

(a) Psychology and philosophy for human behaviors and attitudes and actions.

(b) Natural sciences.

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(c) Engineering/Technology.

(d) Medicine, Hygiene etc.

SAFETY PROGRAMME:-

1. To prevent accidents in the plant by reducing the hazard to minimum.

2. To eliminate accident caused work stoppage and lost production.

3. To achieve lower workmen‟s compensation, insurance rates and reduce all other direct

and

indirect costs of accident.

4. To prevent loss of file, permanent disability and loss of income of worker by eliminating

causes of accidents.

5. To elevate employee‟s morale by promoting safe work place and good working

conditions.

The safety programme must be a planned continued effort to promote plant safety.

An effective safety programme recognizes that accidents are the results of unsafe working

conditions, mechanical hazards and unsafe attitude and actions of workers. Hence the safety

programme should begin with the initial plant installation.

A safety programme includes mainly four E‟s:

1. Engineering: i.e. safety at the design and equipment installation stage.

2. Education of employees in safe practices.

3. Enlistment – It concerns the attitude of employees and management towards the

programme and its purpose. It is necessary to arouse the interest of employees in accident

prevention and safety consciousness.

4. Enforcement – i.e. to enforce adherence to safety rules and practices.

The following activities are carried out under safety programme:

1. Working condition can be improved and standardized thus promoting safety.

2. Periodical surveys of plants, equipment, operations and employees practices are carried

out

to determine actual unsafe practices and conditions.

3. Mechanical safeguards, safety clothing, shoes, goggles and alike may be provided as a

part

of safety programme.

4. The process must be made safes, as it is efficient.

5. Prompt investigation of accident for causes and remedies are carried out and record of

the same is maintained.

SAFETY ORGANIZATION:-

A safety organization consists of a systematic procedure by means of which interest

is created and maintained and all safety standards. The accident prevention is a continuing

process and hence continuous systematic efforts and necessary.

The basic objectives of safety organization are:

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1. Creating and maintaining interest.

2. Fact finding through periodical inspection and surveys of structure, machine tool,

equipment, process and employee procedure, accident investigation and analysis.

3. Selection of remedies and corrective action with regard to unsafe acts and condition

based upon the found facts.

The organization set up consist of

1. Executive safety committee

2. Operation safety committee

1. EXECUTIVE SAFETY COMMITTEE:-

Specific responsibilities and activities are,

1. Review and action on the reports and recommendations of the operation safety

committee

2. Periodically consideration of trends and progressing control of accident frequency and

severity.

3. Approval for abnormal for abnormal expenditures for accident prevention.

4. Approval for major changes in safety organization and of activities effecting matters of

policy.

2. OPERATION SAFETY COMMITTEE:-

The function of the operation safety committee is to execute the policies set up by

the executives‟ safety committee regarding all the phases of accident prevention.

Specific responsibilities of activities of comities includes

1. Study and discuss the principle accident producing condition and circumstances and top

take a recommended practical effective corrective action

2. Review of an action on the reports and recommendation received from the service engg.

3. Review of and action on the reports of the plant safety inspector.

4. Review of and action on accident investigation reports submitted by supervisor.

DUTIES OF PLANT SUPERVISOR:-

1. Supervisor‟s report of accident investigation, the supervisor will carry out immediate

investigation of the accident and report to the operational safety committee to take

corrective action.

2. To take corrective action

3. Daily inspection of premises and equipment under his control with regard to safe

working

condition and processes.

4. Instruct the employees under his control about the safety performance of the work and

also

watch attitudes and physical fitness of workers under his control.

5. Implement the recommendation received from the operation safety committee.

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STEPS TAKEN BY SAFETY ORGANIZATION TO CONTROL ACCIDENTS:-

CONTROL STEPS:-

a. SUPERVISORY SAFETY PERFORMANCE:-

i. Job safety analysis.

ii. Proper job placement.

iii. Development of safe working condition.

iv. Enforcement of safety rules.

b. MENTAL CONDITION OF A PERSON:-

i. Adequate educations and job training.

ii. Safety training, safety awareness.

iii. Regular safety contacts by supervisor.

c. PHYSICAL CONDITION OF A PERSON:-

i. Pre employment medical examination

ii. Periodical medical check up.

iii. Proper job placement.

iv. Adequate medical facilities.

HOW ACCIDENTS CAN BE PREVENTED BY SAFETY PROGRAMMED?

a. Safety code- regarding safe working condition, design maintenance inspection, testing,

etc.

b. Standardization- regarding equipments practices, protective devices

c. Inspection- to secure enforcement of (a) above.

d. Investigation of accidents

e. Research

f. Education and trainings

g. Persuasions/appeal/counseling of employees

h. Insurance

i. Set up full safety department.

SAFE WORK PLACE LAYOUT AND IMPROVEMENT OF WORKING

CONDITIONS:-

A good layout and conditions play a major role in preventing any accidents, which

would have otherwise, occurred.

The following accepts must be considered four safety working condition.

a. Illumination a normal person while performing his daily work places more reliance on

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sight than on any other senses.

b. VENTILATIONS:-

i. To cater the adequate supply of oxygen or air requires for respiration.

ii. To provide thermal comfort by maintaining adequate heat balance of a body.

a. PLANT LAYOUT:-

It should be designed in such manner that it would provide safety and securities of

employees at all costs for preventing accidents. Layout should be such as,

i. Every employee has enough space to move and operate.

ii. Passage ways in between working places roads, tr4acksetc, must never be obstructed.

iii. It prevents inrush of cold/ hot air to the working place.

iv. Floor should be non- skid type, satisfactory plane and must be capable of absorbing

sound

v. House keeping and maintained:

vi. House keeping plays a vary important role. Every thing must be orderly placed in a

suitable position. The willing, work and rest areas, machinery, equipments and tool

should

be kept free from the dirt and dust stain etc. the floor should be regularly clean.

b. NOISE CONTROL:-

i. It is defined as a any undesirable sound. The strength of the sound source is indicated by

the total power in watts that it produces in the air around it.

ii. Effects of n0oises on human beings: it may

a. Annoys the person

b. Disturb sleeps

c. Interface with ability to converse with some one else

d. Damage earrings.

PERSONAL PROTECTIVE DEVICES:-

The personal working in industry extensively uses various types of personal

protective devices and clothing‟s as a safety measures against injury. The devices should

meet following requirements:

1. Adequate protection against the hazards to which the worker will be exposed.

2. Maximum comfort and minimum weight.

3. No restriction on essential movement of the worker.

4. Durability and easy maintenance.

5. Economical.

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PROTECTIVE AND DEVICES:-

1. Head protection. The personal protective equipments used for protecting the head include

helmet, hats, and caps. This are made from aluminum, PVC, fiberglass. In general this

protective headwears should be fire resistance in cases where electrical hazards are

prevented them should be made of non-conductive materials and electrically insulated.

2. Eye and face protection. Numerous eye injuries are caused by dust, flying particles,

splashes and harmful radiations. The devices used for eye protection may be safety

spectacles, mono goggles, impact goggles, welding goggles, welding helmets

3. Hand and arm protection. Protection of hands and arms becomes necessary when workers

have to handle materials having sharp ends. Glows are used for complete protection of

hands are usually provided with wristbands to ensure snug fit. They are made of leather.

4. Foot and leg protection. Adequate protections have to be provided to the worker

employed

in certain job. Risk of injury may be in handling of heavy materials, corrosive liquids wet

conditions, molten metals, and smithy operations.

5. Safety shoes, boots, gumboots are provided protection against the difficulties.

6. Body protection. Sometimes it becomes necessary to provide special protective

equipments

for the body in the form of aprons overalls jackets and suits.

GENERAL SAFETY RULES:-

It is necessary to frame a set of rules to promote safety of employees and to prevent

the direct and indirect cost of accident. Some of the general rules are as follows:

1. Power should be switch of before repairing the equipments.

2. Smoking should be strictly prohibited. Particularly near chemical.

3. Personal protective device like safety goggles, aprons always be used.

4. Wire mesh and safety guards must be provided on all rotating parts.

5. High voltage equipments and other machine that cannot be properly guided should be

fenced.

6. Pressure vessels and there components parts must be periodically tested and defective

replaced.

7. Inflammable materials should be stored separately and away from the general stores.

8. Material handling equipments should have unobstructed path for their movement.

FIRST AID:-

Inspire of taking all safety precautions and measures, accidents cannot be avoided.

An injured worker needs immediate proper treatment. Hence every establishment should

have adequate provisions for first aid treatment.

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AFFORTS BY GOVERNMENT:-

In our country the first factories commission was appointed in 1878 and some

preliminary stage were suggested in the matters of safety. The factories act of 1922

envisaged certain provision of industrial safety and health. The workman‟s compensation

act of 1923 contained provisions for death and disablement benefits. Employees State

Insurance Act 1948. In addition to this Indian Electricity Act 1910, Indian Boiler Act 1923,

Mines Act 1952, Petroleum Act 1934 were also introduced.

All this legislation is made by the Govt. in order to ensure industrial safety. These

Acts govern the safety of personal and equipment in industrial units in country.

To assure safety to workers and elimination chances of damage to machinery and

equipments. Indian standard institute has laid down guideline regarding safety standards,

norms and procedures supplemented by publication of data and safety manual.

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EXPERIMENT.NO: 11

AIM: - TO STUDY ABOUT PLANT MAINTENANCE

INTRODUCTION:-

PLANT:-

A plant is a place, where men, materials, money, equipment machinery, etc, are

brought together for manufacturing products.

MAINTENANCE:-

Today, in modern industry, equipment and machinery are a very important part of

the total productive effort there was the case years ago. Moreover, with development of

special purpose and sophisticated machines, equipment and machinery cost a lot more

money and therefore their idle or downtime becomes much more expansive, for this reason,

it is vitally important that the plant machinery should be properly maintained.

OBJECTIVE TO PLANT MAINTENANCE:-

(i) The objective of plant maintenance is to achieve minimum breakdown and to keep the

plant in good working condition at the lowest possible cost.

(ii) Machines and other facilities should be kept in such a condition which permits then to

be

used at their optimum capacity without any interruption or

(iii) Maintained division of the factory ensures the availability of the machines, buildings

and

services enquired by other sedations of the factory for the performance of their

functions

at optimum return on investment whether this investment be in material, machinery or

personnel.

IMPORTANCE OF MAINTENANCE:-

(i) The importance of plant maintenance varies with the type of plant and its production.

(ii) Equipment breakdown tends to an inevitable loss of production.

(iii) If a piece of equipment goes out of order in a flow production factory, the whole line

will

soon come at a half other production lines may also stop unless the initial flow is

cleared.

(iv) This results in an immediate loss in productivity and a diminution of several thousand

rupees per hour of output.

(v) An improperly maintained or neglected plant will sooner or later required expensive

and

frequed repairs because with the passage of time all machines or other facilities,

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buildings etc wear out and need to be maintained to function properly.

(vi) Plant maintenance play a prominent role in production management because plant

breakdown creates problems such as

1. Loss in production, time

2. Rescheduling of production.

3. Spoilt materials (because sudden stoppage of process damages in process materials)

4. Failure to recover overhands (because of loss in production hours).

5. Need for overtime.

6. Need for subcontracting work.

7. Temporarily work shortages workers require alternative work.

ORGANIZATION STRUCTURE OF MAINTENANCE DEPARTMENT:-

1. Steam 1. Maintenance 1. work orders 1. Engineering 1. Building

2. Power 2. Repair system 2. Design 2. Yards

3. Water 3. Lubrication 2. Planning and 3. Fire

4. Air 4. construction estimating protection

3. Scheduling 4. Waste

4. Backlog control disposal

5. Performance reports.

TYPES OF MAINTENANCE:-

Maintenance can be classified into following categories:

1.Corrective maintenance

2.Scheduled maintenance

3.Preventive maintenance

4.

Maintenance superintendent

Facilities

Foreman

Foreman

shops

maintenance

Foreman

planning and

scheduling

Foreman

engineering

Field foreman

Engineering

assistant

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CORRECTIVE MAINTENANCE:-

Corrective or breakdown maintenance implies that repairs are made after the

equipment fails to perform its normal function. For example, an electric motor will not start,

a belt is broken etc. This practice allows a machine or any other facility to run without

much routine attention, till it actually breaks down and fails to perform its function.

Under such conditions production departments requests the maintenance

departments department to necessary repairs. After removing the faults, maintenance

engineer does not attend the equipment again, until, another failure of breakdown occurs. In

this type of maintenance no attempt is made to prevent the occurrence of breakdown.

Typical causes of equipment breakdown may be as follows:

1. Failure to replace worn out parts.

2. Lack of lubrication.

3. Neglected cooling system.

4. Indifference toward minor faults.

5. External factors such as too low or too high line voltage, wrong fuel etc.

6. Indifference towards equipments vibrations, unusual sounds coming out of the rotating

parts, equipments getting too much heated up etc.

DISADVANTAGES OF BREAKDOWN MAINTENANCE:-

1. The type, gravity, place and time of breakdown is of random nature. This practice leads

to disruption of production plans.

2.It also makes it impossible to plan work load and distribution of maintenance work force

for balanced attention of all equipments.

3.It increases overtime practice and involves prolonged down time due to non-availability

of requisite manpower and spares.

4.It may lead to considerable reduction of output.

5.It becomes difficult to maintain the quality of products.

6.The spoilage of materials is increased due to production of more defective parts.

7.There are increased chances of accidents and less safety to both workers and equipments.

8.It also leads to faster plant deterioration.

9.It cannot be employed for those equipments/items which are regulated by statutory

provisions like cranes, hoists, elevators, electrical installations etc.

SCHEDULED MAINTENANCE:-

The aim of scheduled maintenance is to minimize breakdown. The system provides

for inspection, overhaul, lubrication and servicing of certain machines at predetermined

dates. Overhauling of machines, cleaning of tanks and white washing of building is

normally done in this manner. The frequency of such maintenance job is predetermined and

scheduled or programmed of maintenance work to be done is prepared in advance,

considering available idle time of equipment.

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This system utilize the idle time of equipment without much disturbance in

production schedule. More scheduling, however, is not sufficient. It cannot ensure

completion of work in time because the nature of details of work required to be done

remains unknown. It may therefore lead to increased down time due to non-availably of

requisites skills and materials.

ADVANTAGES OF SCHEDULED MAINTENANCE:-

As compare to breakdown maintenance the scheduled maintenance has the

following advantages

1. It reduces the down time during repairs.

2. The breakdown is minimized and machine run at a higher level of efficiency.

3. Pre-determination of date of commencement of work ensures to plan the work load and

distribution of maintenance work force for balanced attention of all equipment.

This type of maintenance is, therefore, practiced to a certain extent, even in those

companies where breakdown maintenance is done. In fact scheduled maintenance is

compromise between breakdown maintenance and preventive maintenance.

PREVENTIVE MAINTENANCE:-

Preventive maintenance consists of routine actions taken in a planned manner to

prevent breakdown and to ensure operational efficiency to the extent it is economically and

practically possible. In preventive maintenance periodic inspection is carried out to

anticipate breakdowns and to prevent them before they occur, instead of allowing the

breakdown to happen and then to take action. The underlying principle is prevention is

better then cures. Therefore, for adopting preventing maintenance policy, one must have the

data showing the frequency with which machines have maintenance free performance for a

given no of operations hours. From this data the preventive maintenance period for each

machine or a group of similar machines can be set properly. The main objective of

preventive maintenance is to prevent breakdown and to ensure operational accuracy and

safety.

OBJECTIVE OF PREVENTIVE MAINTENANCE:-

1. To minimize the possibility of unanticipated production interruptions by locating or

uncovering any condition this may lead to it.

2. To make plant equipment and machines always available and ready for use.

3. To maintain the value the equipment, machinery and other service facilities by periodic

inspection, repairs, overhauling etc.

4. To reduce the work content of maintenance jobs.

5. Te ensures safety of life of employees.

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DUTIES, FUNCTIONS AND RESPONSIBILITIES OF PLANT MAINTENANCE

ENGINEERING DEPARTMENT:

1. Depending upon size of maintenance department, in have a wide variety of duties or

functions to perform.

2. The work is under the control of plant engineer or maintenance engineer who normally

reports to the works manager.

3. The different duties, functions and responsibilities of the maintenance department are as

follows:

A. INSPECTION:-

1. Inspection is concerned with the routine scheduled checks of the plant facilities to

examine

their condition and to check for needed repairs.

2. Inspections ensure the safe and efficient operation of equipment and machinery.

3. Frequency of inspections depends upon the intensity of the use of the equipment. For

example, bells in a machine may be checked every week; furnace equipment every

month;

an over head bridge crane every four months and so on.

4. Inspection section makes certain that every working equipment receives proper attention.

5. Items removed during maintenance and overhead operations are inspected to determine

the

feasibility of repairs.

6. Maintenance items received from vendors are inspected for the fitness.

B. ENGINEERING:-

1. Engineering involves alterations and improvements in existing equipments and building

to

minimize breakdowns.

2. Maintenance department also undertake engineering and supervision of constructional

projects that will eventually become part of plant.

3. Engineering and consulting services to production supervision are also the

responsibilities

Of maintenance department.

C. MAINTENANCE:-

1. Maintenance of existing plant equipment.

2. Maintenance of existing plant buildings, and other service facilities such as yards, central

stores, road ways, sewers, etc.

3. Engineering and execution of planned maintenance minor installation of equipment,

building end replacements,

4. Preventive maintenance i.e. preventive breakdown by well conceived plans of inspection,

lubrication, adjustment, repair and overhead.

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D. REPAIR:-

1. Maintenance department caries out corrective repairs to alleviate unsatisfactory

conditions

found during preventive maintenance inspection.

2. Such a repair is an unscheduled work often of an emergency nature, and is necessary to

correct break downs and it includes trouble calls.

E. OVERHEAD:-

1. Overhead is a planned, scheduled reconditioning of plant facilities such as machinery,

etc.

2. Overhand involves replacement, reconditioning, reassembly, etc.

F. CONSTRUCTION:-

1. In some organizations, maintenance department is provided with equipment and

personnel

and it takes up construction jobs also.

2. Maintenance department handles construction of wood, bricks and steel structures,

cement

and asphalt paying, electrical installations, etc.

G. SALVAGE:-

1. Maintenance department may also handle disposition of scrap of surplus materials.

This function involves.

2. Segregation, reclamation and disposition of production scrap, and the collection and

disposition of surplus equipments, materials and supplies.

H. CLERICAL JOBS:-

Maintenance department keeps records of

1. of costs

2. of time progress on jobs,

3. Pertaining to important feature of building and production equipment; electrical

installations; water, steam, air and oil lines; transportation facilities etc.

I. Generation and distribution of power and other utilities.

J. Administration and supervision of labor force.

K. Providing plant protection, including fire protection.

L. Insurance administration.

M. Establishing and maintaining a suitable store of maintenance materials.

N. Janitorial service.

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O. HOUSEKEEPING:-

Good housekeeping involves upkeep and cleaning of equipments, building, toilets,

wash-rooms, etc.

P. Pollution and noise abatement.

REQUIREMENT OF GOOD PREVENTIVE MAINTENANCE:-

For achieving maintenance of high order, following are some of the essential

requirements.

1.Good supervision and administration of maintenance department.

2.Priority of maintenance work should be fixed after consultation with production

departments.

3.A good lubrication program should be chalked out.

4.Correct, clear and detailed instruction should be given to maintenance staff.

5.Proper maintenance record should remain in contact with planning and purchasing

department in deciding the type of machine tools to be purchased. A machine tool be

purchased should be of best design and adequately safe. It should have good lubrication

arrangements, minimum of moving parts, and easy availability of spares.

6.Manufactures of machine tool should be dust free and clean with proper ventilation and

illumination.

7.Arrangement of machine should be such that sufficient space is available around the

machine for ease of maintenance work.

8.Failure information must be available in order to have complete knowledge about the

cause of failures and their effects. A systematic approach for maintenance should be

followed.

9.Operator as well as maintenance staff should be well trained.

10.Adequate stock of spares should be kept.

MANAGEMENT TECHNIQUES USED IN PLANT MAINTENANCE:-

A variety of management techniques are used for plant maintenance. These

techniques have led to

1. Increase in maintenance efficiency.

2. Reduced maintenance cost.

3. Improved service.

These management techniques includes,

1. Use of work study.

2. CPM and PERT.

3. Operation research.

4. Use of computers.

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EXPERIMENT.NO: 12

AIM: - WRITE-UP & CASE STUDY ON TPM.

WHAT IS TOTAL PRODUCTIVE MAINTENANCE (TPM)?

It can be considered as the medical science of machines. Total Productive

Maintenance (TPM) is a maintenance program which involves a newly defined concept for

maintaining plants and equipment. The goal of the TPM program is to markedly increase

production while, at the same time, increasing employee morale and job satisfaction.

TPM brings maintenance into focus as a necessary and vitally important part of the

business. It is no longer regarded as a non-profit activity. Down time for maintenance is

scheduled as a part of the manufacturing day and, in some cases, as an integral part of the

manufacturing process. The goal is to hold emergency and unscheduled maintenance to a

minimum.

TPM - HISTORY:-

TPM is an innovative Japanese concept. The origin of TPM can be traced back to

1951 when preventive maintenance was introduced in Japan. However the concept of

preventive maintenance was taken from USA. Nippondenso was the first company to

introduce plant wide preventive maintenance in 1960. Preventive maintenance is the

concept wherein, operators produced goods using machines and the maintenance group was

dedicated with work of maintaining those machines, however with the automation of

Nippondenso, maintenance became a problem as more maintenance personnel were

required. So the management decided that the routine maintenance of equipment would be

carried out by the operators. (This is Autonomous maintenance, one of the features of

TPM). Maintenance group took up only essential maintenance works.

Thus Nippondenso which already followed preventive maintenance also added

Autonomous maintenance done by production operators. The maintenance crew went in the

equipment modification for improving reliability. The modifications were made or

incorporated in new equipment. This lead to maintenance prevention. Thus preventive

maintenance along with Maintenance prevention and Maintainability Improvement gave

birth to Productive maintenance. The aim of productive maintenance was to maximize

plant and equipment effectiveness to achieve optimum life cycle cost of production

equipment.

By then Nippon Denso had made quality circles, involving the employee‟s

participation. Thus all employees took part in implementing Productive maintenance. Based

on these developments Nippondenso was awarded the distinguished plant prize for

developing and implementing TPM, by the Japanese Institute of Plant Engineers (JIPE).

Thus Nippondenso of the Toyota group became the first company to obtain the TPM

certification.

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OBJECTIVES OF TPM:-

1. Achieve Zero Defects, Zero Breakdown and Zero accidents in all functional areas of

the organization.

2. Involve people in all levels of organization.

3. Form different teams to reduce defects and Self Maintenance.

4. Direct benefits of TPM

5. Increase productivity and OPE (Overall Plant Efficiency) by 1.5 or 2 times.

6. Rectify customer complaints.

7. Reduce the manufacturing cost by 30%.

8. Satisfy the customer‟s needs by 100 % (Delivering the right quantity at the right time,

in the required quality)

9. Reduce accidents.

10. Follow pollution control measures.

STEPS IN INTRODUCTION OF TPM IN A ORGANIZATION:-

STEP A - PREPARATORY STAGE:-

STEP-1: Announcement by Management to all about TPM introduction in the

organization

Proper understanding, commitment and active involvement of the top management

in needed for this step. Senior management should have awareness programmes, after

which announcement is made to all. Publish it in the house magazine and put it in the notice

board. Send a letter to all concerned individuals if required.

STEP-2: Initial education and propaganda for TPM

Training is to be done based on the need. Some need intensive training and some

just an awareness. Take people who matters to places where TPM already successfully

implemented.

STEP-3: Setting up TPM and departmental committees

TPM includes improvement, autonomous maintenance, quality maintenance etc., as

part of it. When committees are set up it should take care of all those needs.

STEP-4: Establishing the TPM working system and target

Now each area is benchmarked and fix up a target for achievement.

STEP-5: A master plan for institutionalizing

Next step is implementation leading to institutionalizing wherein TPM becomes an

organizational culture. Achieving PM award is the proof of reaching a satisfactory level.

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STEP B - INTRODUCTION STAGE:-

This is a ceremony and we should invite all. Suppliers as they should know that we

want quality supply from them. Related companies and affiliated companies who can be our

customers, sisters concerns etc. Some may learn from us and some can help us and

customers will get the communication from us that we care for quality output.

STEP C - IMPLEMENTATION:-

In this stage eight activities are carried which are called eight pillars in the

development of TPM activity.

Of these four activities are for establishing the system for production efficiency, one

for initial control system of new products and equipment, one for improving the efficiency

of administration and are for control of safety, sanitation as working environment.

STAGE D - INSTITUTIONALISING STAGE:-

By all there activities one would has reached maturity stage. Now is the time for

applying for PM award. Also think of challenging level to which you can take this

movement.

INDIRECT BENEFITS OF TPM:-

1. Higher confidence level among the employees.

2. Keep the work place clean, neat and attractive.

3. Favorable change in the attitude of the operators.

4. Achieve goals by working as team.

5. Horizontal deployment of a new concept in all areas of the organization.

6. Share knowledge and experience.

7. The workers get a feeling of owning the machine.

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[Figure 12.1: TPM plant wise structure]

CASE STUDY

MRC BEARINGS' TPM JOURNEY: FROM TOTALLY PAINTED MACHINES

TO TAKING PRIDE IN OUR MACHINES

In 1996 MRC Bearings, a unionized aerospace industry supplier recognized it had a

problem. They were behind on their orders. Their customers were pushing for shorter lead

times and cost reductions.

Approximately eighty percent of their maintenance hours were dedicated to

emergency work orders. In October of 1997 over one thousand, six hundred and sixty hours

were consumed by unplanned maintenance in just one area. Ten months later that number

fell to less than thirty hours. That's over a 98% decrease.

In another area they were able to achieve almost a 99% decrease in the number of

unplanned maintenance hours in an eight-month period. Greg Folts, Manager of Continuous

Improvement at MRC attributes their remarkable success to having a hardworking,

dedicated maintenance team and implementing a Total Productive Maintenance (TPM)

program.

"We started slow, beginning with a small area that was critical to our process but

was experiencing chronic problems," said Folts. "At first, a lot of people were skeptical and

not really interested in getting involved with TPM," he said. "We had a core of people who

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were excited about TPM and we enlisted the help of people outside of our organization to

work with us," Folts said. MRC worked with Preston Ingalls, President of Marshall

Institute, to organize their TPM efforts. He continued, "Preston helped us get started, but he

was also our best cheerleader. He got our folks fired up about TPM." One of MRC's

customers, Pratt-Whitney, also supported their efforts by facilitating MRC's first TPM

event and sharing their TPM practices with MRC.

MRC began with a week-long TPM event. Folts explained they would begin by

cleaning, inspecting, lubricating, and performing corrective work on a piece of machinery.

Once a machine was cleaned, it would be painted. At first, people were reluctant to

participate in TPM events. As time went on, people began to notice what improvements

were being accomplished under the TPM events. "In fact, the same people that were

hesitating in the beginning were suddenly asking when their machine would be scheduled

for a TPM event," Folts said.

Rick Staples, an Electrician that has been involved with TPM since its inception

said, "The physical changes are easy to see. Our machines are more reliable, the area is

cleaner and a lot more pleasant atmosphere to work in. Other changes, to those of us that

work here every day, are not as easily detected. For instance; several people who were

totally against TPM at the start, have now willingly participated in TPM workouts or

equipment improvement teams.

Another individual, who one told me to keep my TPM away from his machines,

now is a fully trained TPM Coordinator in his area. It's these types of things that truly

amaze me. The culture change is slow, but it's happening."

MRC formed Equipment Improvement Teams (EITs) to work on resolving

equipment-related issues. Folts credits the EITs with a success that was critical in their

adoption of TPM. He explained they had a piece of equipment with chronic problems. It

was breaking down monthly requiring three or four days each time to fix. He explains, "We

were really frustrated by this problem, we kept fixing it only to see it break down again."

The Equipment Improvement Team took on this problem and discovered the

original manufacturer had used a sub-spec coupling on a drive unit. The problem was

solved by upgrading to the proper coupling. This fix alone increased the efficiency on this

piece of equipment by sixteen percent. "By taking the time to find the root of the failures,

rather than just fixing the symptoms, we were able to solve this problem. In the years

following this repair, the problem was completely eliminated. That success showed a lot of

people in the company that TPM can make everyone's daily life easier as well as improving

productivity," Folts said.

After the initial success, followed by eight TPM events, MRC expanded their TPM

efforts to their second facility. They created a TPM Steering Committee at their second site

and also created a Policy group to coordinate the efforts of both facilities. The President of

MRC Bearings, Bengt Nilsson joined the Policy group as an active member. "Having the

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company president working with us to drive TPM sent a clear message to everyone that this

was not just another flavor of the month program," said Folts.

Don Russell was then solicited to assist in driving the process as the TPM

Coordinator. "We have been very fortunate to have fantastic support from both

management as well as our U.A.W Union personnel," said Russell. In a recent MRC

company newsletter, President Nilsson is pictured shoulder to shoulder with the TPM Area

Coordinators. TPM at MRC has been described as one of the most successful co-

management programs ever started at MRC. Mr. Nilsson said, "I am very pleased and proud

of how the whole organization, after the initial skepticism and hesitation, enthusiastically

embraced the TPM concept. It is of utmost importance to have reliable and well maintained

machinery in order to serve our customers well and to get on-time deliveries. A well

developed TPM program is one of the cornerstones in our drive for manufacturing

excellence."

MRC trained ten TPM Area Coordinators who are dedicated to TPM one week each

month. These TPM Coordinators organize TPM events in their areas, also lead EITs, and

make sure the process keeps working. MRC has begun to create full-time TPM teams. One

such team, comprised of Jeff Franklin, an Electrician and Jim Klugh, a Mechanic, and Jeff

Johnson, an Operator, were able to correct a long-standing equipment problem which

reduced the scrap produced by that equipment to almost zero.

Folts and Russell attribute their success in implementing TPM to seven things.

Russell said, "We realized early on that we couldn't do it all. So we identified a few areas

that we felt were key, we did those things, and we did them well." The areas that MRC

focused on were:

Preventative maintenance

1. Putting predictive maintenance process in place (i.e., vibration analysis equipment)

2. Cleaning the machines, resulting in inspection

3. Creating standards on the equipment for cleaning, lubrication, and daily checks

4. Collecting data on downtime

5. Creating Equipment Improvement Teams

6. Creating TPM Area Coordinators

From this experience, Russell suggests organizations beginning TPM programs start

small and keep it simple.

Did MRC learn any lessons implementing TPM? Folts said, "We learned that

training is a key to being successful with TPM. We did some initial TPM awareness

training for the organization, about one week of training with the operators, and some for

the mechanics. But, looking back we could have had quicker success if we had done more

training." Folts also credits their success to the support of their management, the U.A.W.

union, the hard work of the people at MRC, involvement of Marshall Institute, and the

support of their customers. "Ultimately this is a people issue and we are lucky to have the

right people involved," he said.

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Thinking back about the initial resistance to TPM, Don Russell laughs and says, "At

first a lot of folks here defined TPM as 'Totally Painted Machines'. Now I can say we all

define TPM as 'Taking Pride in our Machines'."

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EXPERIMENT.NO: 13

AIM: - TO STUDY ABOUT ACTIVITY RELATIONSHIP CHART AND ACTIVITY

RELATIONSHIP DIAGRAM

INTRODUCTION:-

The several preceding chapters have dealt with the flow of meter, or other elements,

through the facility being designed. In addition to the element flow around which the

equipment and work centers are arranged, there is the problem of locating the many service

or auxiliary activities. These should be located to serve the productive activity, but in

varying degrees of proximity according to their relative importance to the activity.

The first task is to identify the service and auxiliary activities needed to support the

major activity of the enterprise. In the table types of service the major activity of the

enterprise.

TYPES OF ACTIVITY:-

In the industrial facility there are likely to be a much larger number of services than

indicated in table. A more detailed breakdown is shown in table where the activities are

categorized as serving administration, production, personnel and physical plant. As can be

seen, with a large number of service activities the task of properly relating them to

production, and to each other, can be rather complex. The first task is to identify them all, to

activity of significance is overlooked or ignored.

Also, as pointed out the location of internal activities, as well as flow patterns,

should consider the external relationship to the facility site and its characteristics.

SELECTION OF ACTIVITY CENTERS:-

In choosing the activities or activity centers, the primary characteristics for

consideration are: -

1. Does a single or specialized or particular group of activities occur?

2. Does the activity required significant amount of floor space-say 100ft square more or

less.

3. Does the activities have a lot of flow through it

A study of the organization chart will help to identify activity centers, as will

interviews with key personnel. Then a study of the activity it self should be made to become

familiar with what goes on there. The result of the activity selection process should be a list,

or lists, similar to table.

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DEGREES OF INTERRELATIONSHIP:-

In order to help decide which activities should be located where, a classification of

degrees of closeness has been established, along with a code to identify each. These have

been identified by Richard muther as:

A= absolutely necessary –for the activities under consideration to be next to each other.

E= especially important – for them to be close

I= important –that they be close together

O=ordinary (closeness)-OK as they fall

U= unimportant-for there to be any “geographical” relationships.

It should be recognized that might be a required degree of separations.

THE ACTIVITY RELATIONSHIP CHART:-

The activity relationship chart is an ideal technique for planning the relationship

among any group o f interrelated activities. It is helpful in such cases as:

1. Preliminary allocation of sequence for a from to chart.

2. Relative location of work centers or departments in an office.

3. Location of activity in a service business.

4. Location of work center maintenance or repair operation.

5. Relative location of service areas within a production facility.

6. Showing which activities are related to each other and why,

7. Providing a basis for subsequent area allocation.

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[Figure 13.1: Activity relationship chart for powrarm point]

The activity relationship chart is similar to the from to chart but only one set of

location is indicated. In fact it is again similar to some road map mileage tables, the

distance are replaced by qualitative code latter. Code numbers are entered in the bottoms of

the squares. Representing reasons for each closeness relationship. These codes are:

1. CLOSENESS COLOR CODE:-

A-Red-Absolutely necessary

E-Orange-Especially important

I-Green- Important

O-Blue-ordinary closeness

U- Uncolored-unimportant

X- Brawn undesirable

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2. PRODUCTION RELATIONSHIP:-

1. Sequence of workflow.

2. Use same equipment

3. Use same record

4. Share same space

5. Noise dirt fume vibration etc

6. Facility location

3. PERSONAL RELATIONSHIP:-

1. Share same personal

2. Urgency of contact

3. Degree of personal contact

4. INFORMATION FLOAT:-

1. Use common records

2. Degree of paperwork contact

3. Use same communication equipment

CONSTRUCTING THE ACTIVITY RELATIONSHIP CHART:-

The following interrelationship planning process might proceed somewhat as

follows;

1. Identify all significant services or auxiliary activities needed to support the major

productive functions of the enterprise. Use the plant service activities list in table

2. Separate into categories-a) production b) service

3 Collect data on flow of meter information personal

4 Prepare a form similar to that in fig

5 Enter the activities under analysis down the left hand side the order is not important

6 Enter the desired to represent the relative importance of the relationship –care and

judgments should be exercised in assignment letters to be sure there are not too many.

7 A code number to indicate the reason evolution should be based on knowledge of the

relationship among the activates under consideration and the values of those relationships

with persons connected or use a form to collect permanent data from those person‟s.

8 Review the activity relationship chart with other people to make sure there is some

agreement at the important of relationship it might be wise to obtain approvals from

appropriate people.

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THE ACTIVITY RELATIONSHIP DIAGRAM:-

While the activity relationship chart is useful for planning and analyzing activity

interrelationships, the resulting information is only useful if inventory is converted into a

diagram.

[Figure 13.2: Activity relationship diagram as developed by muther]

The activity relationship diagram is constructed beginning with an analysis of the

activity relationship chart and with the aid of the worksheet shown in fig as follows:

1. List the activity in the left hand column

2. Enter the activity number from the activity relationship chart in each column to represent

the degree of closeness with activity on the line for example on the activity relationship

chart receiving and shipping carries an a relationship to activity 2; an I relationship to

activity 5 an o relationship to activity 6 and 7 a check can be made by verifying that all

activity numbers are for example on line 1 all activity number are included

1,2,5,3,4,8,6,7).

3. Continue the procedure –for each line on the worksheet until all relationship has been

recorded.

4. Enter the identifying activity names in the centers of the corners of the activity templates

as shown in fig us are not transfer since they have been accounted for on the worksheet

and

are unimportant from now on

5. Cut out activity templates from form.

1

0

5 8 7

9 6

4 2 3

1

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7. A range the templates into an activity relationship diagram matching first the A‟s, next

the

E‟, etc.in the most appropriate arrangement. For example no1 might be placed in the

upper

left hand corner of the arrangement as a start then no2 wants to be next to it and then no1

and 5 want to be next to no 2 etc.fig illustrate one possible arrangement satisfying most

of.

the closeness requirement. As with many of the other technique, there is probably no one.

best arrangement. Other trails should be made until all concerned are satisfied. Also an

adaptation of the from-to chart could be constructed and the relationship assigned

numerical values to prove the best answer more quantitatively.

8. Copy final arrangements onto another cross-section sheet as in fig this is the activity

relationship diagram.

9. Draw a tentatice flow pattern if desired on the diagram.

Actually this relatively simple example does not utilize the technique as effectively

as a more complex one. The simpler example is used to illustrate the procedure. Where

there is a large number of activity and relationship, it may be desirable to divide them into

groups of related activities and work first with the larger groups of related activities, or

there is a larger number of service activities than in the accompanying illustration. Then,

the larger function may be more easily related to each other and the process repeated with

smaller activities within the larger ones.

CONCLUSION:-

This practical has covered both procedures and techniques for designing- or

redesigning – interrelationship among a number of activities. It will be found equally useful

in activity relationship planning for any of the types of enterprise referred to in previous

chapters, ranging from schools to post office to mfg plants.

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EXPERIMENT.NO: 14

AIM: - TO STUDY ABOUT DIFFERENT MODELS FOR SELECTION' OF PLANT

LOCATION

Model that attempts to deal with the multidimensional location problem was

developed by brown and Gibson (1972). This model classifies affecting location according

to the model structure, qualifies the criteria, and achieves the balancing or trade-off among

criteria.

CLASSIFICIAT ION OF CRI TERIA:-

The model deals with any list of criteria set by management, but classifies them as

follows.

1. CRITICAL:-

Criteria are critical if their nature may preclude the location of a plant at a particular

site, regardless of other conditions that might exist. For example a water-oriented

enterprise, such as brewery, would not consider a site where a water shortage was a

possibility. An energy-oriented enterprise, such as an Al smelting plant, would not consider

a site where low cost and plentiful electrical energy was not available. Critical factors have

the effect of

eliminating sites for on % decision.

2. OBJECTIVE:-

Criteria that car, be evaluated in monitory terms, such as labor, raw material,

utilities, and taxes are considered objective. A factor can be both objective and critical-, for

example the adequacy of labor would be a critical factor. Whereas labor cost would be an

objective factor.

3. SUBJECTIVE:-

Criteria characterized by, a qualitative type of measurement. For example, the

nature of union relationships and activity may be evaluated, but its monitory equivalent

cannot be established. Again criteria can be classified as both critical and subjective.

MODEL STRUCTURE:-

For each site 1, a location measure LMi is defined that effects the relative values for

each criterion.

LM=CFMi x [X x OFMi + (I -X) x SFMi

Where CFMi = the critical factor measure for site I,

(CFMi = 0 or 1)

OFMi = the objective factor measure for site (0 <= OFMi <= 1, and Ei OFMi = 1)

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SFMi = the subjective factor measure for site (0<= SFMi <-- 1, and E, SFMi ~ 1)

X -1HE OBJECTIVE FACTOR DECISION WEIGHT (0<=x<=I)

The critical factor measure CFMi is the product of the individual critical factor

indexes for site I with respect to critical factor j, the critical factor index for each site is

either 0 or I depending on whether the site has an adequacy of the factor or not. If any

critical factor index is 0, then CM and the overall location model Lau are also 0. Site I

would therefore be eliminated from the consideration

The objective criteria are converted to dimensionless indices in order to establish

comparability between objective and subjective criteria. The objective factor measure for

site OFMi, in terms of the objective factor costs, OFCi is defined as follows.

OFMI = [OFCi x IL (1/ OFCi)]-1

The effect of equation 2 is that the site with the minimum cost will have the largest

OFMi, the relationships of total costs between sites are retained, and the sum of the

objective factor measures is one.

The subjective factor measure for each site is measured by the relative weight of

each subjective factor mid the weight of site I relative to all other sites for each of the

subjective factors. This results in the following statement

SFMi = Ek (SFWk x Swik)

Where SFWk = the weight of subjective factor k relative to all subjective factors, and

SWik = the weight of site I relative to 0 potential sites for subjective factor k

Preference theory is used to assign weights to subjective factors in a consistent mid

systematic manner. The procedure involves comparing subjective factors two at a time/if

the first f actor is preferred over the second then assigned to the first factor and 0 to the

second and vice versa for the opposite result.

Finally, the objective factor decision weight X, must be decided this factor

establishes the relative importance of the objective and the subjective factors in the overall

location problem. The decision is commonly -based on action by a management committee,

reflecting policies, past data, and an integration of wide variety of subjective factors.

With all the data inputs, equation I can be used to compute the location measure,

Lmi for each site and the site that receives the largest Lmi is selected Sensitivity analysis

are shown to indicate how decisions would change when the objective factor decision

weight, X, is varied from 0 to 1.0 the entire procedure has been programmed for electronic

programming using a 0-1 programming algorithm capable of treating problems as large as

150 variables and 50 constraints.

1. SIMPLE MEDIAN MODEL:-

Suppose we want to locate a new plant that will annually receive shipments of

materials from tow sources f I and F2. The plant will create finished goods that must ship to

two distributions warehouses, F3 and F4. Given thest, four facilities, shown in fig. Where

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should we locate the new plant to minimize annual transportation costs for these network

facilities the model.

The simple median model can help answer this question. This model consists the.

volume of 'luau's transported Oil. Rectangular paths. All movements are node in east-west

or north south directions-, diagonal moves are not considered the simple median model

provides an optimal solution.

Table shows the number of loads L1 to be shipped annually between each existing

facility Fl and the new plant; it also shows the coordinate location (Xi, Yi) of each existing

facility F and the cost C to move a lode one distance unit to or from Fi. We let Di be the

distance units between facility Fi and a new plant. The total transit cost, then, Di= I xo - x 1

+1 yo-yi] Notice we calculate the absolute value of the differences, because distances are

always positive. Notice too we could have written

Di= | xo - x | + | yo - yj |

Out goal is to find values for xO and yO that result in minimum transportation costs. We

follow three steps:

1. Identify the median value of the loads li moved.

2. Find the x-coordinate of the existing facility that sends the medium load.

3. Find the y-coordinate value of the existing facility that sends the median load

2. LINEAR PROGRA M MING:-

Linear programming may be helpful after the initial screening phase has narrowed

the

feasible alternative sites. The remaining candidate can then be evaluated, one at a time, to

determine how well each would fit in with existing facilities, and the alternative that leads

to the I best overall system performance can be identified. Most often, overall transportation

cost it‟s the criterion used for performance evaluation. A special type of ham programming

called the distribution or transportation method is particularly useful in location planning I

The success of location planning both affects and is affected by organization control

activities. Since Ulm operations manager fixes many costs with the decision both the

efficiency and effectiveness of the conversion process are upon location. Leading to this

decision are analyses with both modeling and dimensions

3. BREAK EVEN ANALYSIS:-

Break-even analysis is a graphical mid algebraic representation of the relation

among volume of output, costs, and revenues. As the volume of output fro after increases,

costs and revenues also increase. Costs cm) generally be divided in to categories fixed mid

variable Fixed costs we those incurred regardless of volume. They include heating, lighting

and administrative expenses that are the whether one or one thousand units of output are

produced. Variable costs are the fluctuate directly with volume of output. Higher output

results in higher total costs, lower output result s in lower vat-fable costs.

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Break-even analysis identifies the level of output that must tic reached III it recover

though revenues all the costs of operation The break-even point depends on the selling price

of the product and the operating cost structure Some conversion processes. Require high

fixed costs that is, large capital outlays and high overhead expenses - but low unit variable

costs. They require a large volume of output to reach break even but once they have

attained it, profitability increases rapidly, other conversion processes have low fixed costs

and high unit variable cost

4. FACTOR RATINGS:-

Factor ratings are frequently used to evaluate location alternatives because

(1) Their simplicity facilitates communication about why one site is better that another,

(2) They enable, managers to bring diverse vocational considerations into the evaluation

process; and

(3) They foster consistency

Typically, the first step in urging factor ratings is to list the most relevant factors in

the location division. Next, each factor is rated; say from I to 5 according to its relative

importance. Then, each location is rated; say from I to 10 according to its merits on each

characteristic. Finally, the factor rating is multiplied by the location rating lot each factor

and the sum of the products yields the total rating score for that location the total scores

indicate which a 'locations are most promising, consideration of all the various location

factors. This is a decision procedure in which each alternative is rated according to each

factor r relevant to the decision & each factor is weighted according to importance.

STEPS:-

(1) Least most relevant factor in the location decision

(2) Rate each factor according to relative importance.

(3) Rate each location according to it$ merits on each charades VI factor. It 1 f - or rating

by

on rating for each factor.

(4) Multi played location

(5) Multivariate model

MODEL STRUCTURE:-

LMj = (fMj [X*O fMi + (I A) S fMi for each location, a location measure LM, is

defined which reflects relative valued for each criteria. Where (fMi is critical factor

measure for site C ML- =0 or 1)

0 fMi Objective factor measure for site I

(0 < = 0 fMi < = 1)

SMMi Subfactor measure for site

(0<= S Mi <= 1)

X= objective; factor decision weight

(0 < = X < = 1)

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0 fMi =Max ofc - ofci / (Max ofc Min ofc)

SMi is given as = ek (sfwk *swik)

Where sfwk = the wt of sub factor k, related all subfactor.

Smik -Evaluation of site I relative to all potential sites; for sub factor k

Esfwk = 1

0 < = Sfwk < = 1

0 < = Swik <=I & SWik=1 for site with best score on subfactor k

Swik =0 for worst score on subfactor k

6. COMPOSITE MEASURE METHOD:-

(1) Develop a fist of all relevant factors.

(2) Assign a scale to each factor & designate some min

(3) Weigh the scale to each factor & other w*C*t important towards achievements of

system

goals.

(4) Score each potential location according to designated & designated scale & multiply the

Score by weights.

(5) Total the points for each location & either

(a) Use them in with conjunction economic analysis

(b) Include an economics factor in the list & location (III Then basis of max point)

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EXPERIMENT.NO: 15

AIM: - WRITE-UP ON DIFFERENT TYPES OF INDUSTRIAL ACTS/

LEGISLATIONS

1. INTRODUCTION

2. NECESSITY OF INDUSTRIAL ACTS/ LEGISLATION

3. THE INDIAN BOILER ACT, 1923

4. ELECTRICITY ACT

5. THE INDIAN FACTORIES ACT, 1948

6. THE EMPLOYEES‟ STATE INSURANCE ACT, 1948

7. WORKMENS’ COMPENSATION ACT:-

- This act was came into 1st July, 1924

- The workmen‟s compensation (amendment) act, 1976 is the latest amendment which

became effective from 1st October 1976

- “The workmen‟s compensation act provides compensation to certain categories of workers

for the loss of working capacity due to accidents”.

- It safeguards the workers and their families in case of the death or disablements of

workers

arising from accidents.

- Important definitions in the act:

1. DEPENDENT:-

Dependent means any of the following relations of the deceased worker:

a. A widow, a minor legimate son, an unmarried legimate daughter or widowed mother

b. An infirm son or daughter who has attained the age of 18 years and who has wholly

dependent on the earning of workmen at the time of his death.

PARTIAL DISABLEMENT:-

Partial disablement means disablement of temporary nature that reduces the earning

capacity of a workman in the employment in which he was engaged at the time of accident

resulting in the disablement.

TOTAL DISABLEMENT:-

Total disablement means such disablement weather of temporary or permanent

nature, which in capacities a workman for all work which he was capable of performing at

the time of accident resulting in such disablements. The act also specifies certain injuries,

which are to be deemed to result in permanent total disablement.

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APPLICATION OF THE ACT:-

The act applies to all workers employed in railways, factories, mines, mechanically

propelled vehicles, constructional work and other hazardous occupations except persons

employed in a clerical or administrative capacity or in armed forces.

EMPLOYEE’S LIABILITY FOR COMPENSATION:-

If a personal injury is caused to a workman by accident in the course of his

employment, the employer shall be liable to pay compensation in accordance with the

provision of this act if: (a) injury has been caused by accident, (b) during the course of

employment, and (c) has resulted in workman‟s‟ death, permanent or temporary

disablement.

AMOUNT OF COMPENSATION:-

Amount of compensation depends upon the following factors:

1. Avg. monthly wages of workers concerned which should not be more than Rs.1000,

2. The extent of injury, e.g. death, permanent/ total/ partial disablement,

3. Types of work of the worker i.e. weather it is clerical, industrial, administrative,

4. Causes of accidents, means it occurs due to negligence of worker etc.

- After all of this it should be remember that

a. Notice of accident

b. Medical examination

c. Distribution of compensation

d. Occupational diseases

e. Appointment of commissioner

- A worker injured in an accident should first of all give in writing a notice of accident to

the

employer.

7. THE INDUSTRIAL DISPUTE ACT, 1947:-

- It was passed in 1947

- The act makes provision for settlement of industrial disputes between employees and the

employers.

- The main object of the act is to secure industrial peace by setting the industrial dispute

through negotiations and conciliations rather than on the strength of strikers and lockouts.

WHAT IS INDUSTRIAL DISPUTE?

Industrial dispute means any dispute or difference between:

- Employers and employers,

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- Employers and workman,

- Workmen and workmen, which are concerned with: the employment or non-employment

or

the condition of labors of any person.

LOCK OUT:-

Lock out means closing at place of employment or suspension of work or the refusal

by an employer to continue to employ any no. of workers employed by him

STRIKE:-

Strike means refusal to work under a common understanding of any number of

workers. It is the weapon of the workers to compel to employer to accept their demands.

SETTLEMENT:-

It means a settlement arrived at during the course of conciliation proceedings. It

includes a written agreement between the workers and the employers.

MAIN PROVISION OF THE ACT:-

The main provisions of industrial dispute act are:

1. Constitution of the formation of the machinery for settlement of industrial dispute.

2. Strikes and lockouts.

3. Compensation for lay- off and retrenchment.

4. Notice for changes of service conditions.

5. Penalties for break of provision of act.

- The act provides for the prevention as well as settlement of industrial disputes.

- It has provided for extensive and effective machinery for establishing industrial peace.

The

provisions are made in the act for establishing the following machineries for the

prevention

and the settlement of industrial disputes:

Works committee, conciliation, board of conciliation, powers of board, court of

inquiry, labour court, industrial tribunals, national tribunals, strikes and lock outs, penalty

for illegal strikes or lockouts, compensation for lay off and retrenchment, notice for

change of service conditions, closing down the undertaking.

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8. THE PAYMENT OF WAGES ACT, 1936:-

AIM:-

The act regulates the payment of wages to certain classes of persons employed in

industry.

- State govt. can extend the provision of this act to the payment of wages to any class of

persons in industrial establishment.

- The act regulates:

1. The date of payment of wages, and

2. Rules for deduction (fines or otherwise) from wages.

INDUSTRIAL ESTABLISHMENT:-

Industrial establishment means any:

1. Motor transport service carrying passengers or goods or both on hire.

2. Air transport

3. Water supply

4. Mines or oil fields

5. Workshops, where articles are produced with a view to their use, transport or sales.

6. Establishments such as construction, development, maintenance of buildings, roads,

bridges, generation transmission and distribution of electricity etc.

WAGES:-

Wages means all remunerations (salary + allowance) payable to an employee in

respect of his employment,

- Wages also include overtime remuneration, bonus, gratuity, provision, provident fund

contribution by employer, leave salary etc.

IMPORTANT PROVISIONS OF THE ACT:-

1. Payment of wages

2. Deduction from wages

3. Imposition of fines

4. Penalties for offences.

9. THE MINIMUM WAGES ACT, 1948:-

- The payment of wages act was passed in 1948 empowering the central and state

government

to fix minimum rates of wages payable to employees employed in the specific industries.

- It was further revised in 1956 and 1957.

- A minimum wages is of vital importance to the worker‟s health, strength and morale on

one

hand, and for the industrial life, an increased an efficient production on the other hand.

Plant engineering


OBJECTIVES:-

1. To attain the welfare of the labour class through fixing the minimum rate of wages where

it

is not possible to get the reasonable reward from the employment due to the unorganized

character of labour, absence of wages regulating machinery or some such reasons.

2. To prevent exploitation and secure a wages according to the value of the work

corresponding to the productive capacity of the worker.

3. To protect the workers who are unorganized and cannot raise the wages by collective

bargaining.

4. To ensure the industrial peace in the country.

10. THE APPRENTICESHIP ACT, 1961:-

- It was passed by the parliament in 1961 and came into force in 1963.

- In the beginning, this act was framed for training of workers.

- In 1973, the act was amended to provide in plant training to the fresh engineering

graduates

and diploma holders.

- As per the provision of apprenticeship act, it is obligatory on the part of every employer to

engage a specified no. of engg. Graduates and diploma holders as graduate apprentices

and

technician apprentices.

- The no. of apprentices to be trained by the employer is determined by the Director of-

Board

of the Apprenticeship Training of region considered.

MAIN PROVISION OF APPRENTICESHIP ACT:-

- Eligibility for Training for Graduate Apprentice:

1. Degree in engineering or technology.

2. Graduate of professional bodies recognized by state or central government, as equivalent

to

engg.degree.

3. A sandwich course recognized as equivalent to diploma education.

FOR TECHNICIAN APPRENTICE:-

1. Diploma in engineering or technology as recognized by state or central government.

2. Diploma or certificate in a vocational course, involving minimum of two years of study

after completion of secondary education.

PERIOD OF APPRENTICESHIP:-

a. For engg. Graduates and diploma holders, the period of apprenticeship shall be one year.

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However for sandwich course the training under gone during the course of their studies

shall be treated as practical training.

b. These periods of training will be considered as duty period. They are paid stipend during

training period and the rates of stipend are revised from time to time.

MAINTENANCE OF RECORD:-

The employer shall maintain complete record of the apprentice on prescribed

Performa and forward the bio- data of the apprentice to the Central Apprenticeship Advisor

and the Directorate of Apprentice Training. The employer shall also maintain the record of

work done by the apprentice.

11. THE EMPLOYEES’ PROVIDENT FUND AND FAMILY PENSION ACT, 1952:-

- This act was passed in February 1952. The act is applicable to factories and

establishments

falling under notified industry; which have been existence for at least:

(a) 3 years when the number of employees is 50 or more, and

(b) 5 years when the no. of employees is 20 to 50,

(c) It dose not apply to co-operative undertakings employing less than 50 persons and

working without aid of power.

- The object of this act is to provide for installation of provident and family pension

schemes

for the employees in factories and establishments.

CONTRIBUTION TOWARDS PROVIDENT FUND:-

The employees and the employees at the statuary rate as may be specified in the act

shall make the contribution towards provident fund. Usually the employer and the employee

each contribute 8 % of a worker‟s emolument to provident fund.

- The employers are held responsible for remitting their contribution as well as that of

employees towards provident fund. The government shall pay interest on the provident

fund

contribution at the specified rate.

12. EMPLOYEE’S FAMILY PENSION SCHEME, 1971:-

- A provision is made in the provident fund Act for the contribution of family pension fund

with the introduction of Family Pension Scheme, 1971.

- The object of this scheme is to make provision for payment of a pension to the family of a

.

deceased employee if he dies while in employment. If he or she retries after service he is

entitled to get lump sum payment.

- Full benefit is available to those entering the scheme at the age of 25years or below. The

family of a member who has joined this scheme at the age of 60 years would receive a

Plant engineering


pension provided he has been a member of the scheme for a period of not less than 2

years.

- The benefit of the pension will be available to widow until her death or remarriage

whichever is earlier failing which they are available to the eldest surving minor son until

him attains the age of 18 years.

- Failing both the pension benefit is provided to the eldest surving unmarried daughter until

she attains the age of 21 years or her marriage whichever is earlier.

documentpe

Documents

selection of location

plant engineering index

dept production engineering

material handling writeup

safety engineering

semester engineering

raw material centre

raw materials