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Work StudyWork Study
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Why do We Care About Productivity?Why do We Care About Productivity?Why do We Care About Productivity?Why do We Care About Productivity?
Without productivity improvement, businesses do notWithout productivity improvement, businesses do not
survive in a global economysurvive in a global economy..
Higher productivity means higher standard of livingHigher productivity means higher standard of living..
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Ways to Increase ProductivityWays to Increase ProductivityWays to Increase ProductivityWays to Increase Productivity
Increase output using the same or a lesser amount of Increase output using the same or a lesser amount of
resourceresource..
Reduce amount of resource used while keepingReduce amount of resource used while keepingoutput constant or increasing itoutput constant or increasing it..
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Impact of Price/Cost Change on ProductivityImpact of Price/Cost Change on ProductivityImpact of Price/Cost Change on ProductivityImpact of Price/Cost Change on Productivity
When the cost of a resource increases and profit is toWhen the cost of a resource increases and profit is to
remain the same, some combination of the followingremain the same, some combination of the following
must occur must occur::
output is increasedoutput is increased
price price of output is increasedof output is increased
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Factors used forFactors used for
Measuring ProductivityMeasuring Productivity
Factors used forFactors used for
Measuring ProductivityMeasuring Productivity
CapitalCapital -- Number Number of products producedof products produced
divideddivided by asset value by asset value
MaterialsMaterials -- Number Number of products producedof products produced
divideddivided by by amountamount spent on materialsspent on materials Direct Labor Direct Labor -- Number of products produced Number of products produced
divideddivided by direct labor by direct labor--hourshours
OverheadOverhead -- Number Number of products producedof products produced
divideddivided by by amountamount spent onspent on overheadsoverheads
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Work studyWork studyWork studyWork study
Work study is a study of better ways of doing things andWork study is a study of better ways of doing things anddevelops controls by setting standards with respect todevelops controls by setting standards with respect totime.time.
³Methods study´ is the means of improving ways and³Methods study´ is the means of improving ways andmeans of doing things.means of doing things.
The primary purpose of improving µmethods¶ is to saveThe primary purpose of improving µmethods¶ is to savetime and thus effort of time and thus effort of labour labour and machinery.and machinery.
Thus, a measurement of work involved in any job andThus, a measurement of work involved in any job andsetting up standards of time for control purposes normallysetting up standards of time for control purposes normallyexpected is necessary.expected is necessary.
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Foundation of work studyFoundation of work studyFoundation of work studyFoundation of work study
Dr. Taylor¶s conclusion from various experimentsDr. Taylor¶s conclusion from various experiments
was:was:
³The greatest production results when each worker is³The greatest production results when each worker is
given a definite task to be performed in a definitegiven a definite task to be performed in a definitetime in a definite manner.´time in a definite manner.´
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Method StudyMethod StudyMethod StudyMethod Study
The main components of method study areThe main components of method study are
Gaining information about and understanding theGaining information about and understanding the
process, men carrying the process and their work, process, men carrying the process and their work,
machines carrying out the work, tools and workingmachines carrying out the work, tools and workingconditions.conditions.
AnalyseAnalyse the obtained information criticallythe obtained information critically
Chalk out improved alternative methodsChalk out improved alternative methods
Check acceptance and followCheck acceptance and follow--up implementationup implementation
ReRe--evaluate and maintain the method after evaluate and maintain the method after
production is undertaken production is undertaken
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Benefits of methods studyBenefits of methods studyBenefits of methods studyBenefits of methods study
Improved cost performanceImproved cost performance
Improved time performanceImproved time performance
Improved worker satisfactionImproved worker satisfaction
ImprovedImproved standardisationstandardisation of productsof products
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Work MeasurementWork MeasurementWork MeasurementWork Measurement
Work measurementWork measurement refers to the process of estimatingrefers to the process of estimating
the amount of worker time required to produce onethe amount of worker time required to produce one
unit of outputunit of output..
A goal of work measurement is to develop labor A goal of work measurement is to develop labor
standards that can be used for planning andstandards that can be used for planning and
controlling operations.controlling operations.
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Labor StandardsLabor StandardsLabor StandardsLabor Standards
AA labour labour standardstandard is the number of worker is the number of worker--minutesminutesrequired to complete an element, operation, or required to complete an element, operation, or product under ordinary operating conditions product under ordinary operating conditions..
Labour Labour standards are used to plan and controlstandards are used to plan and controloperations.operations.
Labour Labour standards help in determiningstandards help in determining labour labour costscostsand finally help in pricing new products.and finally help in pricing new products.
Labour Labour standards also aid in incentive pay systems.standards also aid in incentive pay systems.
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Labor StandardsLabor StandardsLabor StandardsLabor Standards
A labor standard can be determined using one or A labor standard can be determined using one or
more of the following approaches:more of the following approaches:
Time studyTime study
Work samplingWork sampling Predetermined time standardsPredetermined time standards
HistoricalHistorical standardsstandards
Supervisor estimatesSupervisor estimates
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Time studyTime studyTime studyTime study
Time study is undertaken to set the standard times for Time study is undertaken to set the standard times for
work.work.
Basic systems of time study involveBasic systems of time study involve
Using a stop watchUsing a stop watch Using synthetic time standardsUsing synthetic time standards
Using statistical samplingUsing statistical sampling
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Time StudyTime StudyTime StudyTime Study
Suitable JobsSuitable Jobs
Job performed by a single worker in a fixed locationJob performed by a single worker in a fixed location
Job involves repetitive short cyclesJob involves repetitive short cycles
Job expected to continue unchanged for a long periodJob expected to continue unchanged for a long period Job produces large quantities of outputJob produces large quantities of output
Resulting time standard must be very accurateResulting time standard must be very accurate
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Time StudyTime StudyTime StudyTime Study
Analysts use stopwatches to time the operation beingAnalysts use stopwatches to time the operation being
performed by workers performed by workers
These observed times are then converted into labor These observed times are then converted into labor
standards expressedstandards expressed in minutes per unit of output for in minutes per unit of output for the operationthe operation
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Determining Labor StandardsDetermining Labor Standards
from Time Studiesfrom Time Studies
Determining Labor StandardsDetermining Labor Standards
from Time Studiesfrom Time Studies
ObservedObserved
TimeTime
NormalNormal
TimeTime
StandardStandard
TimeTime
PerformancePerformance
RatingRating
Allowance Allowance
FractionFraction
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Determining Labor StandardsDetermining Labor Standards
from Time Studiesfrom Time Studies
Determining Labor StandardsDetermining Labor Standards
from Time Studiesfrom Time Studies
1.1. Break Break the operation down into basicthe operation down into basic taskstasks
2.2. Determine which cycle of operations are to be timed.Determine which cycle of operations are to be timed.
3.3. Observe and record the elapsed time for eachObserve and record the elapsed time for each of theof the
taskstasks4.4. For each task, estimate the observed worker¶sFor each task, estimate the observed worker¶s
performance rating performance rating. A rating of 1.00 indicates the. A rating of 1.00 indicates the
worker is working at normal speed.worker is working at normal speed.
5.5. Compute the allowance fraction for the operation.Compute the allowance fraction for the operation.(allowance are applied to compensate for personal time,(allowance are applied to compensate for personal time,
fatigue and unavoidable minor delays)fatigue and unavoidable minor delays)
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Determining Labor StandardsDetermining Labor Standards
from Time Studiesfrom Time Studies
Determining Labor StandardsDetermining Labor Standards
from Time Studiesfrom Time Studies
6.6. Compute theCompute the mean observed timemean observed time for each element:for each element:
(Sum of observed element times)(Sum of observed element times)
(Number of cycles timed)(Number of cycles timed)
7.7. Compute theCompute the element normal timeelement normal time for each element:for each element:
= (Mean observed time)= (Mean observed time) xx (Performance rating)(Performance rating)
==
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Determining Labor StandardsDetermining Labor Standards
from Time Studiesfrom Time Studies
Determining Labor StandardsDetermining Labor Standards
from Time Studiesfrom Time Studies
9.9. Compute theCompute the total normal timetotal normal time for the entirefor the entire
operation:operation:
= (Sum of element normal times for all elements)= (Sum of element normal times for all elements)
10.10. Compute theCompute the labor standardlabor standard for the operation:for the operation:
= (Total normal time)= (Total normal time) // (1(1 -- Allowance fraction)Allowance fraction)
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Example: Time Study ApproachExample: Time Study ApproachExample: Time Study ApproachExample: Time Study Approach
In a time study of a manufacturing operation, theIn a time study of a manufacturing operation, the
average time observed to complete a product was 8.6 average time observed to complete a product was 8.6
minutes. The performance rating applied to theminutes. The performance rating applied to the
observed worker was 0.95 and the allowance duringobserved worker was 0.95 and the allowance during
an 8an 8--hour shift was 12.5% or 60 minutes.hour shift was 12.5% or 60 minutes.
Compute the labor standard.Compute the labor standard.
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Example: Time Study ApproachExample: Time Study ApproachExample: Time Study ApproachExample: Time Study Approach
Observed timeObserved time = 8.6 minutes= 8.6 minutes Performance ratingPerformance rating = 0.95= 0.95
Allowance fractionAllowance fraction = 0.125= 0.125
Normal time = Observed time Normal time = Observed time xx Performance ratingPerformance rating
= 8.6 = 8.6 xx 0.950.95
= 8.17 minutes= 8.17 minutes
Standard Time = Normal time / (1Standard Time = Normal time / (1 -- Allowance)Allowance)
=8
.17
/ (1=8
.17
/ (1 -- .125).125)
= 8.17 / (0.875)= 8.17 / (0.875)
= 9.337 minutes= 9.337 minutes
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Uses of time samplingUses of time samplingUses of time samplingUses of time sampling
Aids in setting wages and incentivesAids in setting wages and incentives
Comparing work efficiency of workersComparing work efficiency of workers
Arriving at job schedules for planning productionArriving at job schedules for planning production
Manpower planningManpower planning Helps in product designHelps in product design
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Work SamplingWork SamplingWork SamplingWork Sampling
Work sampling samples the work Work sampling samples the work of one or moreof one or moreemployeesemployees randomly sampled at periodic intervalsrandomly sampled at periodic intervals
TheThe proportion of the total operation that is accounted proportion of the total operation that is accounted
for in one particular for in one particular activity is notedactivity is noted
The results of these studies are usedThe results of these studies are used to setto set labor labor
standardsstandards
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Elements
1 2 3 4 5 Sum Mean Rating
Normal
first
page
.1 .09 .09 .08 .09 1
Collate papers .0
4.03
.04
.06
.05
.9
second
page
.05 .06 .04 .07 .05 1
Collate
papers
.12 .10 .09 .08 .09 .9
Labour standard = total normal time / (1-Allowance time)
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Work SamplingWork SamplingWork SamplingWork Sampling
Suitable JobsSuitable Jobs
Job performed by a single worker in a fixed locationJob performed by a single worker in a fixed location
Job involves repetitive short cyclesJob involves repetitive short cycles
Job expected to be changed periodically as customer Job expected to be changed periodically as customer orders changeorders change
Job produces relatively small quantities of outputJob produces relatively small quantities of output
Resulting time standard used for accounting costResulting time standard used for accounting cost
standard, pricing analysis, and production planningstandard, pricing analysis, and production planning
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Example: Work SamplingExample: Work SamplingExample: Work SamplingExample: Work Sampling
A work sampling study was performed on anA work sampling study was performed on anelectronic assembly operation at OK Instruments.electronic assembly operation at OK Instruments.The study covered an 8The study covered an 8--hour shift with a singlehour shift with a singleworker. The results of the study were:worker. The results of the study were:
ActivityActivity % of Worker¶s Time% of Worker¶s Time
Assemble UnitsAssemble Units 8080
AllowancesAllowances 2020
If If the worker received a performance rating of 1.20the worker received a performance rating of 1.20on the Assemble Units activity and 400 units wereon the Assemble Units activity and 400 units wereassembled during the study, what is the labor standardassembled during the study, what is the labor standardfor this operation?for this operation?
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Example: Work SamplingExample: Work SamplingExample: Work SamplingExample: Work Sampling
1) Compute the average time per assemble:1) Compute the average time per assemble:
= Total Minutes of AssemblyWork = Total Minutes of AssemblyWork
Number of Units Assembled Number of Units Assembled
= .8(480)/400 = .960 minutes per unit= .8(480)/400 = .960 minutes per unit
2) Compute the normal time per unit:2) Compute the normal time per unit:
= (Average Time per Unit)(Performance Rating)= (Average Time per Unit)(Performance Rating)
= .960(1.20) = 1.152 minutes per unit= .960(1.20) = 1.152 minutes per unit
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3) Compute the labor standard:3) Compute the labor standard:
= Normal Time/(1= Normal Time/(1 ± ± Allowance Fraction)Allowance Fraction)
= 1.152/(1= 1.152/(1 -- .20) = 1.44 minutes per unit.20) = 1.44 minutes per unit
Example: Work SamplingExample: Work SamplingExample: Work SamplingExample: Work Sampling
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Predetermined Time StandardsPredetermined Time StandardsPredetermined Time StandardsPredetermined Time Standards
Suitable JobsSuitable Jobs
Job performed by many workers over a compact areaJob performed by many workers over a compact area
Tasks may involve little repetition, but if repetitiousTasks may involve little repetition, but if repetitious ± ±
the cycles are very longthe cycles are very long Workers must be observed by a single analystWorkers must be observed by a single analyst
A moderate degree of accuracy in the labor standardA moderate degree of accuracy in the labor standard
is desirable, but a time study is too costlyis desirable, but a time study is too costly
Only large elements of work need to be observedOnly large elements of work need to be observed
Little detail is needed in setting the time standardLittle detail is needed in setting the time standard
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Predetermined Time StandardsPredetermined Time StandardsPredetermined Time StandardsPredetermined Time Standards
Commonly used for new operations or new productsCommonly used for new operations or new products When labor standard must be determined in advanceWhen labor standard must be determined in advance
of performing an operationof performing an operation
Utilize data that have been historically developed for Utilize data that have been historically developed for
basic body movements, elements of operations, and basic body movements, elements of operations, andentire operationsentire operations
Many predetermined time standard systems are used:Many predetermined time standard systems are used: Work factor Work factor MethodsMethods--time measurement (MTM)time measurement (MTM) Basic motion time (BMT)Basic motion time (BMT) studystudy
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Methods time measurementMethods time measurementMethods time measurementMethods time measurement
The basic MTM approach is to classify human work The basic MTM approach is to classify human work motions into certain fixed standard categories such asmotions into certain fixed standard categories such as
Reach, Move, Turn, Apply pressure, Grasp, EyeReach, Move, Turn, Apply pressure, Grasp, Eye--
motions, bodymotions, body--leg and foot motions.leg and foot motions.
MTM association has done extensive studies on handMTM association has done extensive studies on hand
and body motions and arrived at normal times for and body motions and arrived at normal times for
each of these subeach of these sub--classes of motions.classes of motions.
These are preThese are pre--determined times for motions whichdetermined times for motions whichhelp to set a time standard for a job.help to set a time standard for a job.
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Merits and demeritsMerits and demeritsMerits and demeritsMerits and demerits
It avoids performanceIt avoids performancerating which is subjectiverating which is subjective
It can be used for jobs thatIt can be used for jobs that
are still in the planningare still in the planning
stagestage
There is a definiteThere is a definite
breakdown of motion breakdown of motion
elementselements
A detailed method studyA detailed method study
and work study areand work study are
combined into onecombined into one
It is applicable only for It is applicable only for hand, body and eyehand, body and eye
motionsmotions
Process times for other Process times for other
activities have to beactivities have to beestablished using other established using other
methodsmethods
Ordinary workers areOrdinary workers are
baffled by lengthy details baffled by lengthy details
Detailed analysis involvedDetailed analysis involved
isis time consumingtime consuming
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Subjective MethodsSubjective MethodsSubjective MethodsSubjective Methods
Suitable JobsSuitable Jobs
Any job or group of jobs in which:Any job or group of jobs in which:
Very accurate labor standards are not required, or Very accurate labor standards are not required, or
The cost of time study, predetermined timeThe cost of time study, predetermined timestandards, and work sampling is prohibitivestandards, and work sampling is prohibitive
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Appropriate work measurement techniqueAppropriate work measurement techniqueAppropriate work measurement techniqueAppropriate work measurement technique
A job performed by a single worker in a fixed location. Involves shortA job performed by a single worker in a fixed location. Involves shortrepetitive cycles and is expected to continue relatively unchanged for longrepetitive cycles and is expected to continue relatively unchanged for long periods while producing large quantities of outputs. Very accurate periods while producing large quantities of outputs. Very accurate labour labour standards are requiredstandards are required
A job performed by a single worker in a fixed location. Involves shortA job performed by a single worker in a fixed location. Involves short
repetitive cycles and changes when customers orders for relatively smallrepetitive cycles and changes when customers orders for relatively smallquantities of products change. Labor standards are used for accounting costquantities of products change. Labor standards are used for accounting coststandards, pricing analysis and production planningstandards, pricing analysis and production planning
A job performed by many workers over a compact area. The tasks involveA job performed by many workers over a compact area. The tasks involvelittle repetition; if repetitive they involve long cycles. Workers must belittle repetition; if repetitive they involve long cycles. Workers must beobserved by a single analyst. Moderate accuracy required. Little detail isobserved by a single analyst. Moderate accuracy required. Little detail is
needed in setting standards.needed in setting standards.
Any job or groups of jobs in which very accurate standards are not requiredAny job or groups of jobs in which very accurate standards are not requiredor where cost of time study and other methods is prohibitive.or where cost of time study and other methods is prohibitive.
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Learning CurvesLearning CurvesLearning CurvesLearning Curves
At the start of production runs:At the start of production runs:
Workers are unfamiliar with their tasksWorkers are unfamiliar with their tasks
Time it takes to produce the first few units is highTime it takes to produce the first few units is high
As the workers learn their tasks:As the workers learn their tasks: Their output per day increases up to a pointTheir output per day increases up to a point
Then their output levels off to a rather constant rateThen their output levels off to a rather constant rate
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Learning CurvesLearning CurvesLearning CurvesLearning Curves
Most aircraft manufacturing tasks experience an 80% Most aircraft manufacturing tasks experience an 80% learning ratelearning rate
Labor Labor--hours required to assemble an aircraft ishours required to assemble an aircraft is
reduced by a factor of 0.8 as the production quantityreduced by a factor of 0.8 as the production quantity
doublesdoubles
If first aircraft assembled requires 100 labor If first aircraft assembled requires 100 labor--hourshours
Second aircraft would require 80 labor Second aircraft would require 80 labor--hourshours
Fourth aircraft would require 64 labor Fourth aircraft would require 64 labor--hourshours
Eighth aircraft would require 51.2 labor Eighth aircraft would require 51.2 labor--hourshours
« and so on« and so on
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Learning CurvesLearning CurvesLearning CurvesLearning Curves
10 20 30 40 50 60 70 80 90 100 11010 20 30 40 50 60 70 80 90 100 110 120 130120 130
2020
8080
4040
100100
6060
Unit Number (Unit Number (nn))
120120
Labor Labor--Hours for Hours for nnth Unitth Unit
Aircraft AssemblyAircraft Assembly
80% Learning Curve80% Learning Curve
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Learning CurvesLearning CurvesLearning CurvesLearning Curves
UsesUses and limitationsand limitations
Products and services tend to be customProducts and services tend to be custom designeddesigned
requiring the workers to start from the scratchrequiring the workers to start from the scratch
Batches tend to beBatches tend to be small and hence performancesmall and hence performanceimproves dramatically from the first to the last unitimproves dramatically from the first to the last unit
Product/services tend to be complex.... learningProduct/services tend to be complex.... learning
occurs quicklyoccurs quickly
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