Production & Operation Management

1. CHAPTER 15: WORK STUDY
Responses to Questions
1. Only after a method is chosen, time study done on it is meaningful. On the
other hand, only after a time study is done, a method could be either
improved or finalized. It goes both ways.
2. The ‘therbligs’ would depend on the particular action. For instance, one
may look at the shirt pocket or one may not. One may ‘search’ for the pen
in the pocket or one may not. One may ‘select’ the pen or one may not. In
short, the arrangement and the method are important in time study in
determining the work elements. Shorn of many unproductive elements, the
action could be as simple as involving: ‘Grasp’ and ‘Transport loaded.’
3. The arrangement of the work place, particularly the arrangement of the
stack of sheets is important. In the use of the body, the coordination of the
two hands and the rhythm are important.
4. Depending upon whether one is right-handed or left-handed, one of hands
selects and positions the paper while the other signs.
Hint: First, select the method. Are you going to relocate the paper after
every signature? Are you going to sign them in a bunch of 5 or 10 papers
and then relocate the bunch?
5. Note down the operations, the transports if any, the temporary storages or
delays, and the inspections if any.
6. Purposes of dividing a job into elements are:
(i) to conduct time study or work measurement, and
(ii) to improve the method/process.
Dividing a job into elements facilitates the above purposes – e.g. a method
can be improved element by element.
7. (i) Manufacturing budget:
Method study will indicate: a) equipment to be used, b) material to be
used, c) manpower requirement, and d) energy and other supplies
requirement.

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Time study will indicate the rate at which the production can be achieved
and the rate of use of the resources.
(ii) Production Plan:
The above information can be used in deriving a production plan.
(iii) Personnel Policies:
The jobs difficulties, the fatigue levels are the additional information that
could be useful in designing the personnel policies.
(iv) Materials Planning:
The work study will indicate: a) material to be used b) rate of use of
material c) the time at which materials are needed.
8. Value Engineering involves shaving off unnecessary cost-producing
items/materials and wherever possible improving on the components/
materials to provide better value.
Method Study and Time study also involve, similarly, shaving off cost-
effort-time consuming unnecessary elements of work.
One improves the value; the other improves the productivity.
9. The system is in:
a. arranging the information e.g. by means of process flow charts,
man-machine charts;
b. the process of critical examination of the above information.
10.The efforts of a Method Study will come to a nil result, if the ‘improved’
method is ‘not acceptable’ to the people who are going to use/implement
it.
Time study results will be contested for its subjective components such as
Performance Rating and Allowances (particularly that part which places
responsibility on management). Acceptability is an important aspect of
Work Study. Good industrial relations (IR) will make the atmosphere more
conducive for accepting changes.
11.The quantum of the work of the cleaners per unit time can be established
based on a Work study. A suitable measure of work (specific measurable
result) has to be established.
This is not difficult in the case of the cleaners, although it is perceived as
indirect work in industrial context. For instance: (i) number of rooms
cleaned per hour by a cleaner ; or (ii) the given shop-floor to be cleaned
every time in so much time by the cleaner crew.

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Supervisor’s work can also be measured by the quantum of work achieved
by his team members. He is fully accountable – even in the quantitative
sense – for the work of his team. Captain of the Cricket team is
accountable in terms of the percentage of wins.
12.Work study is good only when it actually produces the desired results. The
supervisor is there to monitor and control the work, material and human
dimensions. A good supervisor produces the desired harmony between
these dimensions.
13. MTM can be used when the time can be broken down into small TMUs
i.e. when a series of standardized micro-motions would apply to the work
situation. An example is the work on a watch assembly.
PMTS need not always consist of micro-motions, but the job must have
standardized work packets. Sewing of garments in a clothing factory could
use PMTS data such as Standard Sewing Data.
Where the work does not fall into standardized micro-motions or work-
packets, one has to use custom-built work elements and their
measurement by a stop watch. Fig 15.4 in the book is one such example.
In practice, one comes across the non-standardized situations more often
than the standardized work situations. Therefore, stop-watch time study
finds application widely.
14.MTM elements for the right and left hands are given below. We assume
that the person is familiar with the layout on the table and is a practiced
hand, just as would be the case in an industry.
Left hand TMU Right hand TMU
RB 12 12.9 RB 12 12.9
G1A 2.0 G1A 2.0
MB 12 13.4 MB 12 13.4
TS 180 9.4 TS 180 9.4
(10X2) M3B 114.0
(=5.7X10X2)
(10X2) M3B 114.0
TS 180 9.4 TS 180 9.4
MB 12 13.4 MB 12 13.4
RL 1 2.0 RL 1 2.0
TOTAL 166.5 TOTAL 166.5
Left and right hands are assumed to work simultaneously. However, there are
no difficult simultaneous motions.

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Time required = 166.5 TMU = 166.5 x 0.036 seconds = 5.994 seconds.
We have assumed a Performance Rating of 100.
Note: This is NOT a professional or trained MTM analysis. The above
example and solution are given only for illustrative purposes in the class-
room.
15.The ‘coarser’ tuning is actually for finer aspects such as motivation of
employees, and orientation of their objectives in line with the corporation’s
goals. These aspects are, obviously, much more important than the
increased efficiencies achieved through Work study. The MD was,
therefore, referring to the ’tuning’ of the organization towards the
employees and the resultant ‘tuning’ of the employees towards the
organization.
16. MTM application needs specialised training.
Even a stop-watch time study needs much experience in: (a) division of
work into identifiable elements for time measurement, (b) spotting foreign
elements and non-work elements, (c) performance rating, (d) working with
the employees and seeking their co-operation.
Time study is a sensitive matter and, therefore, seeking cooperation is a
vital aspect of the study.
17.Advantages of the second generation PMTS system are:
1. Takes less time; saves on time for the study.
2. As the numbers of Motions are fewer, there are less variations
between different analysts.
Disadvantage is:
1. Accuracy of the results is lower.
18. Work Sampling can be used in situations where the work components
appear randomly, whereas stop-watch time study in generally performed
for jobs that have a definite repetitive cycle. When an office secretary does
the job elements of typing, file-keeping – on the computer and physically,
attending to telephone-calls and the customers/visitors, these job
elements do not appear in a definite repetitive cycle. In such a case, Work
Sampling would be useful.
However, Work Sampling can also be used for setting production
standards like those resulting from a stop-watch time study.

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19. We have the following data:
Total output = 306 pages
Total time = 6.5 x 10 = 65 hours over 10 days
Person Total No. of observations Typing observations Perf. Rating
CT-1 117 37 80
CT-2 117 40 90
CT-3 117 36 120
CT-4 117 37 100
Allowances are 15 per cent.
Normal Time=6.5 X10 37 X 80 + 40 x 90 + 36 x120) + 37 x 100
_____ 117 100 117 100 117 100 117 100
306
= 0.2647 hour per page
= 15.88 minutes
Standard Time = (15.88) / (1 - 0.15) = 18.68 minutes per page.

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CHAPTER 15: WORK STUDY
Objective Questions
1. O & M is:
a. a synthetic time standard
b. the Maintenance time standard
√c. Work Study in an office
d. Ogilvy & Mather system of Work Study
2. Work Factor is:
√a. a PMTS
b. the allowance given in MTM
c. the performance rating
d. a data block for clerical work standards
3. The advantage of MTM is:
√a. it avoids performance rating
b. it avoids the use of allowances
c. a & b
d. none of the above.
4. The disadvantage of MTM is:
a. it does not indicate performance rating
b. it can only be used in office situations
c. it does not have effects of sample size coming into the
picture
√d. none of the above
5. If the normal time is 1 minute and the allowances are at 17 per cent,
the standard time is:
a. 0.85 minute
b. 0.83 minute
√c. 1.20 minute
d. 1.17 minute
6. If the observed average time is 1 minute, performance rating is 110
and the allowances are 17 per cent, the standard time is:
a. 0.75 minute
b. 0.91 minute
c. 1.06 minute
√d. 1.32 minute

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7. Ratio Delay Study refers to:
√a. Work Sampling
b. allowances given in time study
c. study that led to performance ratings
d. none of the above
8. TMU pertains to:
a. time study method for maintenance
b. Method study in office work
c. sample size in Work Sampling
√d. MTM
9. The main difference between a stop-watch time standard and a
synthetic time standard is that the latter
a. is more accurate
b. does not need ‘allowances’
√c. does not use ‘performance rating’
d. all of the above
10. In Work Sampling the following formula is used for determining the
number of observations to be made:
n = 4 p (1 - p) / E2
This formula corresponds to:
√a. 95 per cent confidence level
b. 97.5 per cent confidence level
c. 99.7 per cent confidence level
d. confidence level has no connection with the above formula
11.The first step in performing a time study is to:
a. select a proper operator for observation.
b. statistically determine the adequate number of cycles required
to be observed.
c. decide on the precision needed.
√d. see that the work follows the prescribed method.
12.One ‘time measurement unit’ in MTM corresponds to:
a. 0.001 hour
b. 0.0036 hour
c. 0.0036 minute
√d. 0.0006 minute

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13.‘SIMO’ refers to:
√a. motions that are simultaneous.
b. a sampling method used in office work measurement.
c. a method of incentive calculation based on time standards.
d. none of the above.
14.Normal Time is always:
a. greater than the Standard Time
b. equal to the average of the observed times
√c. smaller than the Standard Time
d. equal to the average of the observed times divided by the
performance rating.
.