UNIT4 :I ) WORK STUDY METHOD STUDY

&

WORK MEASUREMENT

METHOD STUDY :EXAMPLE

ElmntNo.,

Element Symbol

Time(Minutes)

Remarks

1 Put on computer Op 0.2

2 Wait W 0.1

3 Computer is on Op 0.1

4 Msg(Fan Failure) Op 0.05

5 Check Msg Op 0.1

6 Telephone Technician Op 0.2

7 Wait W 15.0

8 Technician Checks Ins 1.2

9 Tells to send to Lab Op 0.2

10 Telephone for attender Op 0.1

ElmntNo.,

Element Symbol

Time(Minutes)

Remarks

11 Wait W 30.0

12 Attender transports

Trans 3.2

13 On Repair Table Storage

1440.0

14 Technician inspects

Ins 5.6

15 Tech removes Fan Op 7.2

16 Walks to stores Trans 3.0

17 Waits W 9.0

18 Takes new fan,signs

Op 5.0

19 Walks to Lab Trans 3.1

20 Fixes new fan O 8.2

ElmntNo.,

Element Symbol Time(Minutes)

Remarks

21 Inspects Ins 2.5

22 Calls for attender O 1.2

23 Waiting W 10.5

24 Attender carries it Trans 2.2

25 Connect to system O 1.2

26 Put on system O 0.3

27 Inspects fan working Ins 2.2

28 Start work O 0.2

Operations 13 24.15

Inspections 5 11.6

Transportns

4 11.5

Delays 5 64.6

Storage 1 1440.0

Total 1551.85 25.86 Hrs

UNIT4 :I ) WORK STUDY Work study: It is defined as that body of

knowledge concerned with the ANALYSIS OF WORK METHODS AND EQUIPMENT used in performing a job, the DESIGN OF AN OPTIMUM WORK METHOD and the STANDARDISATION OF PROPOSED WORK METHODS.

The purpose of work study is to determine the best or most effective method of accomplishing a necessary operation

Time study and motion study are results of practices developed by F.W. Taylor, Frank and Lillian Gilbreth.

I.1 ) METHOD STUDY Method study is also known as methods

improvement, that eliminates wasteful and inefficient motions.

Industrial Engineering—Work Study—Method Study—Process Charts—Process Charts Symbols

“METHOD STUDY is the systematic recording and critical examination of EXISTING and PROPOSED WAYS of DOING WORK as a means of DEVELOPING and APPLYING EASIER AND MORE EFFECTIVE METHODS and REDUCING COSTS” (B.S.I)

6 steps Method study procedure • Select/Record/Examine/Develop/Install/

Maintain

METHOD STUDY

6 steps Method study procedure • Select• Record• Examine• Develop• Install• Maintain

METHOD STUDY METHOD STUDY – USE OF PROCESS CHARTS : Process Charts Symbols are utilized for

simplifying the Recording of the Method. The symbols represent different types of

events. Circle to represent Operation , Square for

Inspection, Arrow for Transport, Triangle for Storage and D for Delay ( first two provide value addition

Process Charts used in Method Study Outline process chart/Operation process chart/Flow

process charts/Two handed process chart/Multiple activity chart/The man machine chart or worker-machine chart /Flow diagram/String diagram/SIMO chart

MOTION STUDY& MICRO MOTION STUDY

Motion study is the science of eliminating wastefulness resulting from using unnecessary; ill-directed and inefficient motion. The aim of motion study is to find and perpetuate the scheme of least waste methods of labour.

Micro motion study provides a valuable technique for making minute analysis of those operations that are short in cycle, contain rapid movements and involve high production over a long period of time.

Micro-motions are also known as ‘Therbligs’.

THERBLIGS

1.Search (Sr)

2.Select (St)

3.Grasp (G)

4.Transport empty (TE)

5.Transport loaded (TL)

6.Hold (H)

7.Release load (RL)

8.Position (P)

9.Pre-position (PP)

10.Inspect (I)

11.Assemble (A)

12.Disassemble (DA)

13.Use (U)

14.Unavoidable delay (UD)

15.Avoidable delay (AD)

16.Plan (Pn)

17.Rest for overcoming fatigue (R)

18.Find (F)

PRINCIPLES OF MOTION ECONOMY& METHOD STUDY TOOLS

Principles of motion economy are divided into three groups.

a. Effective use of the operator

b. Arrangement of the workplace

c. Tools and equipment

Method Study Tools: Motion study, Facilities Layout, Work

Simplification, Flow process Charts, Ergonomics

I.2 ) WORK MEASUREMENT This form an important part of work study, itself a

sub part of Industrial Engineering. The dependency may be shown as Industrial Engineering—Work Study—Work

Measurement(Time Study) Def: “TIME STUDY is a work measurement

technique for recording the time and rating for the elements of a specified job carried out under specified conditions and for analyzing the data so as to obtain the time necessary for carrying out the job at a defined level of performance by a qualified and trained worker” (B.S.I)

Qualified worker

WORK MEASUREMENT TECHNIQUES :

Direct Time Study/ Synthesis Method/Analytical Estimating./Pre determined Motion Time System

(PMTS)./Work sampling or Activity Sampling or Ratio Delay Method.

Work measurement involves 7 STEPS. 1.Break the job into elements/2.Record the observed time for each element

by means of either time study, synthesis or analytical estimating./3.Establish elemental time values by extending observed time into normal time for each element BY APPLYING A RATING FACTOR./4.Assess relaxation allowance for personal needs and physical and mental fatigue involved in carrying out each element./5.Add the relaxation allowance time to the normal time for each element to arrive at the work content.

/6.Determine the frequency of occurrences of each element in the job, multiply the work content of each element by its frequency (i.e., number of time the element occurs in the job) and add up the times to arrive at the work content for the job./7.Add contingency allowance if any to arrive at the standard time to do the job.

5METHODS OF WORK MEASUREMENT1.TIME STUDY Time study is concerned with the determination of the amount of time

required to perform a unit of work. Objective of time study is to establish the standard time. Time study by stop watch: The steps involved are 1. Select the job to be studied2. Select the worker to be studied3. Conducting stop watch time study SYNTHESIS METHOD

Synthesis Method: Building up the time required to do a job at a defined level of performance.

3. ANALYTICAL ESTIMATINGAnalytical Estimating: Used to determine the time values for jobs having long and non-repetitive operations.

4. PREDETERMINED MOTION TIME SYSTEM (PMTS) PMTS: Normal times are established for basic human motions.

METHODS OF WORK MEASUREMENT5. WORK SAMPLING OR ACTIVITY SAMPLING OR RATIO-

DELAY METHODWork sampling helps determine allowances for inclusion in standard times.

The work sampling study consists of essentially the following steps:1. Determine the objective of the study, including definitions of the states

of activity to be observed.2. Plan the sampling procedure including:

(a) An estimate of the percentage of time being devoted to each phase of the activity.

(b) The setting of accuracy limits.(c) An estimation of the number of observations required.(d) The selection of the length of the study period and the

programming of the number of readings over this period.(e) The establishment of the mechanics of making the

observations, the route to follow and the recording of data.3. Collect the data as planned.4. Process the data and present the results.

METHOD STUDY- BENEFITS& WORK MEASUREMENT - BENEFITS Method Study- Benefits: Productivity Improvement , Further

method Improvements, Optimisation of Resources, Cost Reduction, Profitability improvement, Competitive edge, Industrial growth, Improvement of Country’s Economy

Work Measurement - Benefits: Productivity measurement &

Improvement , Man power planning, Design of Wage Incentive Schemes, Cost Budgetting , Performance Measurement, PPC, M/C capacity planning, Further method Improvements

WORK MSMNT PROBLEMS Q1)Observed timing=20 Seconds , compute Normal/Basic

time ?If Rating is 80%, Normal/Basic time= 20*0.80=16 SecsIf Rating is 125%& 100%,, respective Normal/Basic times:

20*1.25=25 Secs &20*1.00=20 SecsQ1.1) Normal/Basic timing=20 Seconds; If Rating is 80%, Observed time= 20/0.80=25 SecsIf Rating is 125%/100%, respective Observed time= 201.25=16

Secs& 20/1.00=20 Secs

Q2)OT=1.53 Mins, R=80%, Allowances=16%, compute N.T , S.T, Production standards, productivity productivity?(NT=OT*R,ST=NT*(1+R), productivity =Output/man-hour,output/man-shift etc)

N.T=1.53*0.80=1.224 Mins/Item , S.T=1.224*1.16=1.41984, Production standards =60/1.41984=42.26 Items/hour,42.26*8=338 Items/shift, 338*3=1014 Items/ Day

& productivity = 42.26 Items/ man-hour,42.26*8=338 Items/man-shift, 338*3=1014 Items/ man-Day

WORK MSMNT PROBLEMS

Q3)In an 8hours plant study, prodn=320 nos.,, idle time=15%, Performance rating=120%, Allowances=12% of Normal time, Determine standard time / unit produced?

prodn=320 nos in 8 hours(480 Mins), Actual Production time=480 – 15%

*480=480-72=408,OT=408/320= 1.275 NT= OT* R= 1.275*1.20=1.53 ST=NT* (1+R5)=1.53*1.12=1.7136 Production Standard =

60/1.7136=35/Hour. 35*8=280/Shift, 280*3=840/Day

Q4)AN INDUSTRIAL ENGINEER CONDUCTED A TIME STUDY FOR A JOB AND STUDY RESULTS ARE SUMMARISED.(TIME IN MINS, RA=12%,CA=3%). IDENTIFY &REMOVE OUT LIERS.COMPUTE BASIC TIME & S.T FOR THE JOBElmt

C1 C2 C3 C4 R Ttl avg NT=

OT*R

12%

RA=

NT*0.12

3%

CA=

NT*

0.03

1 1.246 1.328 1.298

1.306 90 % 5.178

1.295 1.166

2 0.972 0.895 0.798

0.919 Mc

100

3.584

0.896 0.896

3 0.914 1.875 1.964

1.972 100 % 5.811

1.937 1.937

4 2.121 2.198 2.146

2.421 110 % 8.886

2.222 2.444

5 1.253 1.175 1.413

2.218 100 % 3.841

1.280 1.28

T 7.72 0.92 0.23 8.88

WORK MSMNT PROBLEMS

Problems on work sampling: Refer Text book