Work measurement techniques involve breaking down jobs into individual elements called therbligs. The time required to complete each therblig is recorded and analyzed to determine a standard time for the job. This standard time accounts for the basic time of the elements as well as allowances for things like fatigue and special conditions. The overall goal is to set an efficient standard that maximizes productivity while preventing overexertion by workers.

1. WORK MEASUREMENT TECHNIQUES
Soumya Subhra De
Research Scholar ,SIF, CUSAT

2. What is Work Study / Work Measurement:
• Organized common sense
• 10% technique and 90% psychology
Objectives of Work Study:
Obtain the optimum use of the human and
material resources available to the
organization for the accomplishment of the
work

3. DEFINITION
• According to the British Standards Institute
“work study is a generic term for those
techniques, particularly method study and work
measurement, which are used in examination of
human work in all its contexts and which lead
systematically to the investigation of all factors
which affect the efficiency and economy of the
situation being renewed, in order to effect
improvement.”
• Work study consists of as already mentioned in the
above definition of two steps –
• Method study (motion study)
• Work measurement (time study)

4. Principles of Work Study:
• Must come from the top level
management.
• People made aware of the objectives and
the need of the exercising such study.
• Method study must precede work
measurement

5. Scheduling A Work / Task
WAGE PLANNING
JOB DESIGN Work METHOD STUDY
Schedule
WORK MEASUREMENT

7. PRINCIPLES OF MOTION ECONOMY
Also called “the characteristics
of easy movement” (British
Standards)
Developed by Frank Gilbreth
As a young building contractor,
he found ways to make
bricklaying faster and efficient
process.
He find ways to increase output
and make jobs easier.

8. Principles concerning the economy of
movements which have been developed
from direct experimentation
Form a good basis for the development
of improved methods at the workplace.
Classified as three main types:
A.Use of human body,
B.Arrangement of the workplace,
C.Design of tools and equipment

9. USE OF HUMAN BODY:
The two hands should begin and
complete their movements at the same
time.
The two hands should not be idle at the
same time except during periods of rest.
Motion of arms - symmetrical and in
opposite directions
Hand and body motion - lowest
classification

10. USE OF HUMAN BODY:
Continuous curved movements are
to be preferred than straight-line
motion
Rhythm is essential to the smooth
and automatic performance of a
repetitive operation.
Work should be arranged so that
eye movements are confined to a
comfortable area, without the
need for frequent changes of
focus.

11. ARRANGEMENT OF WORK PLACE:
Definite and fixed station for all tools
and materials
Tools and materials should be pre-
positioned to reduce searching. Gravity
feed, bins and containers should be
used wherever possible
Materials and tools should be arranged
to permit the best sequence of motions.
The color of workplace should contrast
with that of the work and thus reduce
eye fatigue.

12. ARRANGEMENT OF WORK PLACE:
“Drop deliveries” or ejectors should be
used wherever
Provision should be made for adequate
lighting, and a chair of the type and
height to permit good posture should
be provided.
The height of the workplace and seat
should be arranged to allow alternative
standing and sitting.

13. DESIGNS OF TOOLS AND EQUIPMENTS:
Two or more tools should be combined
wherever possible.
Where each finger performs specific
movements, the load should be distributed
Handles such as those on cranks and large
screwdrivers should be designed
Levers, crossbars and hand-wheels should be
so placed that the operator can use them
with the least change in body position and
the greatest “mechanical advantage.”

15. DEFINITION
 According to British Standard Institution “Motion
Study is the systematic recording and critical
examination of existing and proposed ways for
developing more effective and easier methods to
reduce cost.”

16. STEPS IN MOTION STUDY
SELECT
RECORD
EXAMINE
DEVELOP
INSTALL

17. SELECTION OF JOBS
 Economic Aspects
 Technical Aspects
 Human Aspects
Economic Basis of Job Selection
Bottleneck of Operation
Activity involves excessive labors
Operation producing larger amount of scraps
Backtracking of materials.
Human Basis of Job Selection
Workers complaining about unnecessary and tiring
of work
More frequency of accidents
Inconsistent earning

18. RECORDING
 CHARTS
 DIAGRAMS AND MODELS
 PHOTOGRAPHIC AID

19. CHARTS
 Outline process char ts
 Flow process char ts
 Multiple activity char ts
 Two handed process char ts
 Simultaneous motion cycle

20. OUTLINE PROCESS CHART
Principal operations
and inspections of
the processes are
diagrammatically
represented in the
chart

21. FLOW PROCESS CHART
OPERATION
INSPECTION
TRANSPORT
DELAY
STORAGE

22. MULTIPLE ACTIVITY CHART
Simultaneous / interrelated activities of operators and machines
are described on a common time scale.

23. TWO HANDED PROCESS CHART
Activities of a worker’s hands are recorded in
their relationship to one another is called
“Two handed process charts”
Advantages:
1. Enables the work study person to gain intimate knowledge
about the details of the job.
2. Enables to study each element of the job by itself and in its
relation to other elements.
3.From this study, ideas for improvements are developed.
4. The chart can be applied to assembly, machining and even
clerical jobs

24. SIMO CHART
 It is a graphic representation of the
sequence of the therbligs or group of
therbligs performed by body members of
operator. It is drawn on a common time
scale. In other words, it is a two-hand
process chart drawn in terms of therbligs
and with a time scale.

25. DIAGRAMS AND MODELS
 Flow diagram
 String diagram
 Two and three dimensional diagrams,
models and templates

26. PHOTOGRAPHIC AIDS
 CYCLOGRAPH
 To make a cycle graph, a small electric bulb is attached
to the finger, hand, or any other part of the body whose
motion is to be recorded.
 By using still Photography, the path of light of bulb (in
other words, that of the body member) is photographed
by keeping the working area relatively less illuminated.
 The resulting picture (cycle graph) shows a permanent
record of the motion pattern employed in the form of a
closed loop of white continuous line with the working
area in the background.

27.  CHRONO CYCLOGRAPH
 The Chrono cycle graph is similar to the cycle graph, but
the power supply to the bulb is interrupted regularly by
using an electric circuit. The bulb is thus made to flash.
 The procedure for taking photograph remains the same.
The resulting picture instead of showing continuous line
of motion pattern, shows short dashes of line spaced in
proportion to the speed of the body member
photographed.
 Wide spacing would represent fast moves while close
spacing would represent slow moves. The jumbling of
dots at one point would indicate fumbling or hesitation of
the body member.
 A chrono cycle graph can thus be used to study the
motion pattern

28. EXAMINING
o Examine facts without any bias
o Avoid hasty judgments / conclusions
o Do not consider new method until all undesirable features
of existing method have been exposed
Function:
If unnecessary, eliminate the activity altogether
Combine activities, if feasible
Change sequence of activities so that work or delay is reduced
Simplify the activity to reduce the work content or the time
consumed by examination
TOOLS
Questions: Primary (What is to be done?)
Secondary (What else can be done?)
Alternatives (What should be done?)

29. DEVELOPING
 Draw a framework of an improved method by
arranging in sequence the essential ‘do’
operations.
 Fill up ancillary work in a way as efficient as
possible
 Try out mock ups of the new method (make dry
runs)
 Draw up improved method in process chart form

30. INSTALLING
 It involves two phases. They are Preparation of
plan like who will plan? how to plan?
 Arrangement for working according to plan
like Training, Advise
MAINTAINING
 It requires to make allowances for changes. Result
of suggestion schemes and Minor innovations
introduced by workers / supervisors were added to
the core findings in subsequent time

32. UTILITY
1. Recording the times and rates of working for the
elements of a specified job carried out under
specified conditions.
2. Analyzing the data so as to obtain the time necessary
for carrying out the job at a defined level of
performance.

33. STEPS IN TIME STUDY
1. Select the Job for Study
2. Break the operation into small elements or
Therbligs depending upon the nature of the job
and the purpose of the study
3. Determine number of cycles to be timed
4. Observe and record time at each therbligs
5. Calculate Normal Time
6. Calculate performance Rating
7. Determine Allowances
8. Derive Standard Time

34. Selecting a job for time
study
 The job in question is a new one
 If a change in material or method of working has
been made then a new time standard is required.
 A complaint has been received about the time
standard for an operation.
 A particular operation appears to be “bottleneck”
 Standard times are required prior to the
 introduction of an incentive scheme.

35. Qualified worker
 One who is accepted as having the necessary physical
attributes, who possesses the required intelligence,
education, and has acquired the necessary skill and
knowledge to carry out the work in hand to satisfactory
standard of safety, quantity and quality.
 A representative worker is one whose skill and
performance is the average of the group under
consideration. She/He may not necessarily be a qualified
worker.

36. Breaking The Job Into Elements
 The job in question is a new one
 If a change in material or method of working has been
made then a new time standard is required.
 A complaint has been received about the time standard
for an operation.
 A particular operation appears to be “bottleneck”
 Standard times are required prior to the introduction of
an incentive scheme.

37. Reasons for breakdown of job
 To ensure that productive work (or effective time) is separated
from unproductive activity (or ineffective time).
 To permit the rate of working to be assessed more accurately
than would be possible if the assessment were made over a
complete cycle.
 To enable elements involving high fatigue to be isolated and to
make the allocation of fatigue allowances more accurate.

38. ELEMENTS
• A repetitive element is an element which occurs in every work
cycle of the job.
• An occasional element does not occur in each work cycle of
the job, but which may occur at regular or irregular intervals.
e.g. machine setting.
• For a constant element, the basic time remains constant
whenever it is performed. e.g. switch the machine on.
• A variable element is an element for which the basic time
varies in relation to some characteristics of the product,
equipment or process, e.g. dimensions, weight, quality etc.
e.g. push trolley of parts to next shop.

39. • A manual element is an element performed by a worker.
• A machine element is automatically performed by a power-
driven machine (or process).
• A governing element occupies a longer time than any of the
other elements which are being performed concurrently.
e.g. boil kettle of water, while setting out teapot and cups.
• A foreign element is observed during a study which, after
analysis, is not found to be necessary part of the job. e.g.
degreasing a part that has still to be machined further.

40. Recording Time For
Activities
Cumulative timing
• The watch runs continuously throughout the study.
• At the end of each element the watch reading is recorded.
• The individual element times are obtained by subsequent
subtractions.
• The purpose of this procedure is to ensure that all the time
during which the job is observed is recorded in the study.
• Typically, most work-study persons attain fair degree of
accuracy quickly when using the cumulative method.

41. Flyback time
• The hands of the stopwatch is returned to zero at the end of
each element and are allowed to start immediately, the time
for each element being obtained directly.
• In a comparative study of two methods carried out the
Purdue University, the average error in reading the watch
using the cumulative method was +0.000097 min per reading
and using the flyback method was -0.00082 min per reading.

42. Differential timing
The elements are timed in groups, first including and then
excluding each small element.
• Typically used for short element short cycle work,
where elements are so short that there is not enough
time for study-person to look at the watch and make a
recording.
• In this process, either the cumulative or the flyback
method of watch manipulation may be used.

43. Rating
• Rating is the assessment of the worker’s rate of working relative to the
observer’s concept of the rate corresponding to the standard pace.
• It is a comparison of rate of working observed by the work-study person with
a picture of some standard level.
• The standard level is the average rate at which qualified workers will
naturally work at a job, when using the correct method and when motivated
to apply themselves to their work.
• This rate of working is called standard rating.

44. • If the standard pace is maintained and the appropriate
relaxation is taken, a worker will achieve standard
performance over the working day.
• Standard performance is the rate of output which qualified
workers will naturally achieve without over-exertion as an
average over the working shift provided they know and
adhere to the specified method and, they are motivated to
apply themselves to their work.
• This performance is denoted as 100 on the standard rating
and performance scales.

45. • The purpose of rating is to determine from the time actually taken by
the operator being observed the standard time which can be
maintained by the average qualified worker and which can be used as
a realistic basis for planning, and incentive schemes.
• Time study is concerned with speed at which operator carries out the
work, in relation to the concept of normal speed.
• “Speed” here means the effective speed of operation.

46. Factors affecting rate of
working
1. Variation in the quality or other characteristics of the material used,
although they be within the prescribed tolerance limit.
2. Changes in the operating efficiency of tools or equipment within their
normal life.
3. Minor and unavoidable changes in methods or conditions of operations.
4. Variation in the mental attention for the performance of elements.
5. Changes in the climatic and other conditions.

47. Rating factor
• The figure 100 represents standard performance.
• If the operator is apparently performing with less
effective speed, than the assigned factor is less than
100.
• If, on the other hand, the effective rate of working is
above standard, the operator gets a factor above
hundred.
• Essential idea being:
Observed time x Rating = Constant

48. • This constant is known as the basic time:
Rating
Observed time x = Basic Time
Standard Rating
• So, depending on the rating assigned for the operator,
the basic time can either be less than or greater than
the observed time.

49. Selected time
Constant element
• A very high or short observed time for a given element of
job should be treated with caution.
• An exceptionally high observed time could be due to
incorrect recording, but most common reason is material or
environment variation.
• In such as case, it should be checked whether such a
variation is frequent or rare.
• Excess observed time because of rarely occurring events
is typically not included as a representative.

50. Variable element
• In general more observations will be necessary of a variable element
than of a constant element before reliable representative basic times
can be established.
• The analysis of factors affecting the time to complete the element
should be closely studied.
• Some relationship should be established between the observed time
and the variable factors.
• Multiple factors could be affecting the observed time variation and
establishing relationships amongst multiple factors is difficult.

51. Work content
• The work content of a job or operation is defined as: basic time+
relaxation allowance+ any allowance for additional work (e.g. the part of
relaxation allowance that is work related).
• Standard time is the total time in which a job should be completed at
standard performance – i.e. work content, contingency allowance for
delay, unoccupied time and interference allowance.
• Allowance for unoccupied time and interference may not be frequently
included in the standard time calculations; however, the relaxation
allowance is.

52. Standard time
constituents
• A contingency allowance is a small allowance of time which may be
included in a standard time to meet legitimate and expected items of
work or delays, precise measurement of which is uneconomical
because of their infrequent or irregular occurrence.
• Contingency allowance for work could include fatigue allowance;
whereas the allowance for delay could be dependent on the workers.
• Typically contingency allowances are very small and are generally
expressed as percentage of the total repetitive minutes of the job.
• 5%

53. • Relaxation allowance is an addition to the basic time
intended to provide the worker with the opportunity to
recover from the physiological and psychological effects of
carrying out specified work under specified conditions and
to allow attention to personal needs.
• The amount of the allowance will depend on the nature of
the job.
• One of the major additions to the basic time.
• Industrial fatigue allowance, in turn, forms a major portion
of the relaxation allowance.
• Relaxation allowances are also given as percentages of the
basic times.
• 12-20%

54. Other allowances
 Start-up / shut-down allowance
 Cleaning allowance
 Tooling allowance
 Set-up / change-over allowance
 Reject / excess production allowance
 Learning / training allowance
 Policy allowance is an increment, other than the bonus increment,
applied to standard time to provide a satisfactory level of earning
for certain level of performances under exceptional conditions.

55. Standard time Calculation
• Now, we can add all the constituents to arrive at the standard
time for a job.
Standard time = observed time + rating factor +
relaxation allowance + work related contingency
allowance + delay related contingency allowance.