ch5 process+analysis

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Process Analysis

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• Process Analysis

• Process Flowcharting

• Types of Processes

• Process Performance Metrics

OBJECTIVES

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Process Analysis Terms

Process: Is any part of an organization that takes inputs and transforms them into outputs

Cycle Time: Is the average successive time between completions of successive units

Utilization: Is the ratio of the time that a resource is actually activated relative to the time that it is available for use

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Process Flowcharting Defined

Process flowcharting is the use of a diagram to present the major elements of a process

The basic elements can include tasks or operations, flows of materials or customers, decision points, and storage areas or queues

It is an ideal methodology by which to begin analyzing a process

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PROCESS ANALYSISStandard Symbols used for Flowcharting

Symbol Activity Definition of Activity

Operation Modification of an object

Transportation or Movement

Change in location of an Item

Inspection

Examination of an Object (Qlty/Qty parameters)

Delay/Temporary Storage

Retention of an Object in a location awaiting next activity

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Decision Point (Awaiting decision on further Action)

Location awaiting next activity

Storage Items in stored condition (no unauthorized removal)

Combined Activity

Two activities occur simultaneously

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PROCESS ANALYSIS – Key Terms

• What is a process?A process is any part of an organization that takes Inputs and transforms them into Outputs

• Cycle time the elapsed time between starting and completing a job

(unit item) (Average time between completion of units)

• Run time is the time required to produce a batch of parts

(for the batch) (this is calculated by multiplying the time required to

produce each unit by the batch size)

• Set-up time is the time required to prepare a m/c to produce an item

(for the m/c)

8• Operation time is the sum of set-up time and runtime for a batch

(for the Batch) of parts that are run on a m/c

• Thro’put time the time that the unit spends actually being ( for the Unit) worked plus the time spent waiting in a Q

• Thro’put Rate is the Output rate that the process is expected to (for the Batch) produce over a period of time

• Value Added time the time in which useful work is actually being

(for the unit) done on the unit

• Thro’put Ratio Process Velocity :

the ratio of the total thro’put time to the value added

time

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• Make-to-order A process that is activated only in response to an (Either Unit or actual order Batch)

• Make-to-stock A process that produces standard products that are (Either Unit or stored in finished Goods Inventory : the product is Batch) quickly delivered to the customer

• Hybrid Combines the feature of both make-to-order and (Unit or Batch ) make-to-stock

(A generic product is made and customised in a final process to meet actual orders)

Make-to-Order

customer

Production

Product

Customer Order

Make-to-Stock

customer

Forecast orders

Production

Finished Goods Inventory

Product

Customer OrderProduct

Assemble-to-Order

customer

Forecast orders

Production of Subassemblies

Inventory

of Subassemblies

Customer order

ProductAssembly

of the Order

Subassembly

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Efficiency Actual Output

Standard Output

Productivity Output

Input

Utilization Time activated

Time available

Little’s Law Thro’put time = Work-in-Proccess

(definition as follows) Thro’put Rate

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Example: Flowchart of Student Going to School

Yes

No

Abstain

Go to school today?

Walk to class

Drive to school

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Types of Processes

Single-stage Process

Stage 1

Stage 1 Stage 2 Stage 3

Multi-stage Process

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Other Process Terminology (Continued)

Bottleneck– Occurs when the limited capacity of a process

causes work to pile up or become unevenly distributed in the flow of a process

– If an employee works too slow in a multi-stage process, work will begin to pile up in front of that employee. In this case the employee represents the limited capacity causing the bottleneck.

Pacing– Refers to the fixed timing of the movement of

items through the process

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Other Types of Processes

Make-to-order

– Activated only in response to an actual order

– Both work-in-process and finished goods

inventory kept to a minimum

Make-to-stock

– Process activated to meet expected or

forecast demand

– Customer orders are served from target

stocking level

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Process Performance Metrics

Operation time = Setup time + Run time

Throughput time = Average time for a unit tomove through the

system

Velocity = Throughput time

Value-added time

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Process Performance Metrics (Continued)

Cycle time = Average time betweencompletion of units

Throughput rate = 1 . Cycle time

Efficiency = Actual output Standard Output

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Process Performance Metrics (Continued)

Productivity = Output

Input

Utilization = Time Activated

Time Available

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Cycle Time Example

Suppose you had to produce 600 units in 80 hours to meet the demand requirements of a product. What is the cycle time to meet this demand requirement?

Suppose you had to produce 600 units in 80 hours to meet the demand requirements of a product. What is the cycle time to meet this demand requirement?

Answer: There are 4,800 minutes (60 minutes/hour x 80 hours) in 80 hours. So the average time between completions would have to be: Cycle time = 4,800/600 units = 8 minutes.

Answer: There are 4,800 minutes (60 minutes/hour x 80 hours) in 80 hours. So the average time between completions would have to be: Cycle time = 4,800/600 units = 8 minutes.

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Process Throughput Time Reduction

Perform activities in parallel

Change the sequence of activities

Reduce interruptions

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Question Bowl

Which of the following are possible examples of “cycle times”?

a. Time for each television to come off an assembly line.

b. Time it takes for a stock purchasec. Time it takes for an instructor to grade

an examd. Time it takes to complete an automobilee. All of the above

Answer: e. All of the above

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Question Bowl

Which of the following are used as symbols in a Process Flowchart?

a. Decision pointsb. Blockingc. Starvingd. Bottlenecke. All of the above

Answer: a. Decision points (A diamond shaped symbol.)

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Question Bowl

Which type of process is configured as follows?

a. Single-stage processb. Multi-stage processc. Make-to-order processd. Make-to-stock processe. All of the above

Answer: b. Multi-stage process

1 2 3

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Question Bowl

When an assembly line employee is waiting

for a unit of work to come down the line so

they can stop being idle and get back to

work, it is an example of which of the

following process terms?

a. Buffering

b. Blocking

c. Starving

d. Bottleneck

e. All of the above

Answer: c. Starving

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Question Bowl

When a company waits until they have an order for their product in hand before beginning any production for that order, we can characterize their operation as which of the following processes?

a. Single-stage processb. Multi-stage processc. Make-to-order processd. Make-to-stock processe. All of the above

Answer: c. Make-to-order process

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Question Bowl

If the Run Time for a batch of parts is 45 minutes on a machine, and the Setup Time is 65 minutes, which of the following is the Operation Time?

a. 75 minutesb. 110 minutesc. Only 45 minutesd. 65/45 minutes or 1.44 hourse. Can not be computed on the data above

Answer: b. 110 minutes ( Operation Time is the sum of Run Time and Setup Time, or 65 + 45 = 110 minutes)

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Question Bowl

If the standard expected phone calls for a

telephone marketers is 24 per hour, and one

telephone marketer did 27 per hour, which of

the following can be used to describe their

Efficiency?

a. 88.8%

b. 100%

c. 112.5%

d. Well over 150%

e. Can not computed on the information given.

Answer: c. 112.5% (Ratio of actual performance/expected performance, or (27/24) x 100 = 110 minutes)

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Solved Problems – OPERATIONS MANAGEMENT(Class of 2010)

Q5. A processor makes 2 components, A and B, which are then packed together as final product (each product sold contains one A and one B). The processor can do only one component at a time: either it can make As or it can make Bs. There is a setup time when switching from A to B

Current plans are to make 100 units of component A, then 100 units of component B, and then 100 units of A and 100 units of B to be packed to be supplied as 100 units of Final ProductThe setup and runtimes for each component are given below:-

Assume that packaging of 2 components is totally automated and takes only 2 seconds / unit of the final product. The packaging time is small enough that you can ignore it. What is the average hourly output in terms of no. of units of packaged products (which includes 1 of A and 1 of B)

Component Setup / Changeover Time

Run Time / Unit

A 5 min 0.2 min

B 10 min 0.1 min

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Answer. In order to make final goods, we have to assemble both component A and component B.

So, let us find out the final operation time for both the components :-

Component A

Operation Time = Setuptime + Runtime (for batch)

= 5 + [ (0.2 × 100)]

= 25 minutes

Component B

Operation Time = Setuptime + Runtime (for batch)

= 10 + [ (0.1 × 100)]

= 20 minutes

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So, Total Operation Time for 100 nos. of Finished Products ( Excluding Packaging Time)

= 25 + 20

= 45 minutes / 100 pcs

Now, to find out Average output per Hour

In 45 minutes - - - - - - 100 nos

60 minutes - - - - - - ?

= 60 × 100 = 133.34 units

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Therefore Average Output per Hour = 134 units