A work sampling investigation of white collar workers (female-clerical)
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A WORK SAMPLING INVESTIGATION
OF WHITE COLLAR
WORKERS (FEMALE-CLERICAL)
by
Hemen C. Parekh
B.S., University of Gujarat, 1955
Submitted to the Department of
Mechanical Engineering and the
Faculty of the Graduate School
of the University of Kansas in
partial fulfillment of the
requirements for the degree of
Master of Science.
March, 1958
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ACKNOWLEDGEMENTS
The author wishes to express his
appreciation to Prof. E. G. Lindquist, Dr. R. N. Bradt and Prof. Max Fessler
for their assistance and guidance in the pursuit of this investigation.
Gratitude is extended to Mr. Robert Vosper, Director of Libraries, Mr. Keith
Nitcher, Comptroller, and Mr. James Hitt, Registrar, all of the University of
Kansas, for their kind permission to conduct this investigation in their
respective departments. The indebtedness to the workers of all the departments
is cheerfully acknowledged. Without their understanding cooperation, the effort
would have been lost in a maze of meaningless figures.
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TABLE OF CONTENTS
|
Section |
Page |
|
ABSTRACT |
1 |
|
PURPOSE |
2 |
|
INTRODUCTION TO THE THEORY OF
WORK SAMPLING |
3 |
|
DEFINITION OF ACTIVITY-ELEMENTS |
6 |
|
DESIGN AND EXECUTION OF THE
SAMPLING PLAN |
8 |
|
DISCUSSION OF RESULTS |
15 |
|
SUMMARY OF DATA AND
CALCULATIONS |
28 |
|
Tables |
29–78 |
|
Charts |
79–87 |
|
APPENDIX |
88 |
|
Sample Observation Sheet |
89 |
|
CONCLUSION |
90 |
|
BIBLIOGRAPHY |
92 |
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A WORK SAMPLING INVESTIGATION
OF WHITE COLLAR WORKERS (FEMALE-CLERICAL)
ABSTRACT
This investigation was carried
out to determine the distribution of the work-effort of clerical workers into
the different work-activities. It was also intended to determine the amount of
time spent on personal needs by the above group of workers and compare it with
the personal and/or fatigue allowances reported by various authors in texts on
motion and time study.
In the four departments selected,
a total of 30 workers were observed. Fourteen work- and delay-activities were
listed on an observation sheet and some of them were further qualified by such
suffixes as "a," "b," "w," and "p."
The workers were observed at all
times of the working hours, except official rest periods, using a scheme of
systematic sampling. The purpose of the investigation was made known to the
workers prior to the beginning of actual observations, to ensure a normal and
relaxed atmosphere.
An examination of the computed
data shows that although there is considerable variation in the productivity of
the different departments, the percentage of the total personal delays is
consistent from one department to another. This again varies significantly
within each department, as does the "direct work" and supporting
delays. There is enough evidence to believe that, within each department,
individual workers have stable work patterns, although at different levels.
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A WORK SAMPLING INVESTIGATION
OF WHITE COLLAR
WORKERS (FEMALE-CLERICAL)
PURPOSE
In 1910, the clerks and the
kindred workers formed 10.2 per cent of the total work force in U.S.A. In 1954,
the same group formed 19.5 per cent of the total. In this age of strong
competition, the management is increasingly faced with the problem of cost
reduction. There is a constant effort to widen the existing areas of cost
reduction, and the search for new fields continues. Thus it is consistent, both
from an operating and an economic view point, that the management should have
complete knowledge of the amount of time actually consumed by different types
of delays among the white collar group.
The purpose of this research is
to determine, using statistical methods, the relative amount of time spent on
different work activities by a group of white collar workers and to provide,
through representative measure, the estimate of the rates of different types of
non-productive activity.
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INTRODUCTION TO THE THEORY OF
WORK SAMPLING
Sampling, in statistical
references, is defined as the process of drawing inferences concerning the
characteristics of a mass of items, by examining closely the characteristics of
a somewhat smaller number of items drawn from the entire mass. "Sample,"
is the term used for this small number, and "population," or
"universe," is the term for the large mass.
Work sampling marks the beginning
of the use of statistical methods to cope with the variability inherent in work
measurement. It advocates taking qualitative observations in a random manner
over a protracted interval, as opposed to the classical procedures of
"interruption study," which require that quantitative observations be
taken over a continuous but limited period.
Work sampling is based upon the
laws of probability, which are well illustrated by the examples of coin tossing
and drawing beads from a bowl, where the distribution of the universe is known
in advance. It will not be undertaken here to enumerate the different laws of
probability, but a brief discussion of the Binomial Theorem is in order.
In work sampling, most authors
assume the simplest possible model—that, under conditions of random sampling,
the probability of finding the activity in question in a particular state is
the same throughout the period of study. Under this assumption, the relative
frequency with which "X" of the "n" observations are to be
found in a particular state, when the probability of finding any one
observation in that state "p," is given by the binomial distribution:
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f(x/n) = n!
------------------- p^x (1-p)^(n-x)
x! (n-x)!
where 0 ≤ p ≤ 1
0 ≤ x ≤ n, x is an integer.
For this simple binomial model, the sample proportion (x/n) is an
unbiased estimator of the probability "p"—the average of the sample
proportions from an infinitely large number of samples from the same
population would be equal to the probability "p." Thus, the
estimating
formula does not introduce a bias.
The variance of the sample proportion, a measure of its precision
as an estimator, is given by the expression:
Var (x/n) = p(1-p)
-------
n
Since the probability "p" is unknown, an approximation to the
variance is obtained by substituting for the unknown "p" its
estimator,
the sample proportion (x/n).
In general, there are three common methods of sampling:
1. Random Sampling
2. Systematic Sampling
3. Stratified or Selective Sampling
It is difficult to define "randomness," but it can be described as
a method of drawing samples where "no apparent order" or connection
between and/or among items is present. A human being is a poor randomizing
device; hence, one of the following methods is usually adopted for random
sampling:
1. Card Randomization
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Page No.: 5
Card are prepared with the days
and the minutes marked on them, mixed well and then drawn, one at a time; the
day and the minute is noted down and the card replaced before another drawing.
The required number of samples are obtained in this way and then ordered
chronologically.
2. Table Randomization
From any arbitrary number in the
random number table, the digits are read, either horizontally or vertically,
four at a time. The first number is associated with the day of the week, the
second number with the hour of the day, and the third and fourth numbers,
together, represent the minute of the hour. N samples are obtained in this way
and then ordered chronologically.
Systematic sampling is a method
in which a regularly ordered interval is maintained between items chosen. A
great deal of work sampling is performed using some form of systematic
sampling. If there is no cyclic behavior present in the phenomenon under study,
systematic sampling is acceptable, and certainly advantageous from an operating
point of view.
In many applications of work
sampling, where it is suspected that the probability of finding the activity in
a given state does not remain constant, stratified sampling is resorted to.
Here the population is divided into periods, or strata, in each of which the
probability is assumed to remain constant. Advantageously, the allocation of
observations among periods can be proportional to the length of the period and
either random or systematic sampling is used in making the observations. It has
been shown that proportionally allocated stratified sampling is always at least
as precise as the simple random sampling, which is appropriate for the binomial
model.¹
Reference:
- Richard W. Conway, "Some statistical
aspects in work sampling,"
Journal of Industrial Engineering, March–April, 1957, p.107.
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DEFINITION OF THE ACTIVITY
ELEMENTS
1. Writing Operations
Writing with pen or pencil, on
papers, forms, cards, and so forth.
“Make ready” and “Put away” included.
2. Handle Papers
Papers, forms, slips, cards in
hand; sitting or standing; all arm and body motions except walking.
3. Operate Office Equipment
Operating all mechanical and
electrical equipment such as typewriter, adding machine, duplicating machine,
stamping and paper-punch, photographic equipment, and so forth.
4. Conversation
A. Pertaining to work,
with co-workers or outsiders.
B. Personal conversation with anybody.
5. Filing
Taking out from or putting into
drawers or regular files, papers, cards, and so forth.
6. Walking
Walking empty handed or with
papers, cards, books or anything else in hands.
“Getting up” from chair or “Sitting down” on chair, before or after “walking”
included.
7. Absent
A. Not in sight; out of
work area on business.
B. Not in sight; out of work area on personal needs.
8. Use Telephone
Receive incoming calls or make
calls to outside.
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9. Counter Service
Attending to outsiders at window or counter, exchanging information, or making
business transactions.
10. Wait on Customer
Not used
11. Make Sale
Not used
12. Delay
Receive instructions from supervisor; wait for supervisor; obtain supplies;
sharpen pencil; clean table; unavoidable accidents, such as spill ink; raise
window shade and like.
13. Miscellaneous
Usually reading, checking, verifying, and so forth, connected with
"operate office equipment" and other major elements.
14. Relax
Attending to personal needs while on the work station, read newspapers, or just
idle.
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DESIGN AND EXECUTION OF THE
SAMPLING PLAN
A work sampling investigation is
usually divided into three phases as follows:
A. Preparing for Work Sampling
- Deciding upon the main objectives or purposes of
the study.
- Obtaining the approval of the supervisor of the
department in which the work sampling study is to be made.
- Announcing the fact that the study will be taken.
B. Performing Work Sampling
- Classifying into elements the activity to be
studied and describing in detail each element to be measured.
- Designing the observation form.
- Determining the number of observations to be made,
the number of days over which to continue the study, the time for taking
the observations, the number of workers to be included in the study, the
confidence level, the accuracy of the estimates, and other details.
- Observing activity and recording data.
C. Evaluating and Presenting
Results of Work Sampling
- Evaluating the validity of the data.
- Evaluating the reliability of the data.
- Determining the accuracy of the data.
- Analyzing and presenting the data in forms of
tables, charts, etc.
- Drawing conclusions.
Note:
The discussion here will be confined to the first two phases, and the… (text
appears to be truncated in the image)
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third phase of the investigation
will be dealt with under "Discussion of Results."
The purpose of the study has been
stated under the same heading; hence, no reiteration is necessary.
After the main objectives of the
study were formulated, the departmental heads of the departments selected were
approached and the purpose of the study was explained to them. The
whole-hearted support received was more than expected. Assurance was given that
all efforts to conceal the identity of the departments and the workers observed
will be made. Accordingly, in the presentation of the results, the departments
are identified by the capital letters A, B, C, and D; while the workers within
each department are identified by small letters a, b, c, and so forth. It was
also pointed out that the sampling plan would involve little direct contact
with the workers being observed and, as such, would not be a hindrance to them
in carrying out their assigned duties.
After obtaining the approval of
the departmental heads, further details were discussed with the immediate
supervisors in charge of the workers. The need to announce the fact that the
study will be taken and to explain the purpose of the study to the workers to
be observed was stressed. In all but one department, this announcement was made
by the supervisor and the purpose briefly explained. Later in the course of the
study, questions of the individual workers were answered by the observer from
time to time.
In a work sampling study, the
need to seek worker cooperation cannot be exaggerated. It is essential that the
workers should proceed with their work in the normal manner during the period
of the study. This is
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one of the main reasons why, in
the present investigation, a scheme of systematic sampling was adopted,
although the work sampling literature recommends the random sampling method. A
biased formula can give biased estimates, but of greater importance in work
sampling is the bias introduced through a poor design and execution of the
sampling plan.
In most work sampling
applications, the observer makes trips of the different work stations at random
intervals. In fact, if the work stations are spread over a large area, there is
no other choice for the observer except to make trips. This further limits the
type of sampling to random sampling, in order to avoid introducing a bias. If
the trips are made at regular intervals (systematic sampling), it is obvious
that the workers would anticipate the appearance of the observer or that the
trips might coincide with certain periodical elements of the activity.
Now even if the trips are made at
random, the workers may be expected to change their behavior at the appearance
of the observer. To the extent that the worker can anticipate the time of
observation and is able to alter the state of activity that will be observed,
work sampling is susceptible to a very serious amount of bias.
Now these difficulties can be
eliminated if the observer can observe the activities of any one of a group of
workers, from a single observation post. Under such a method, firstly, a
systematic sampling is possible and desirable. Secondly, a worker certainly
cannot know at what instance he is being observed. It was believed that this
system would result in a relaxed atmosphere in which the workers would work in
their normal fashion. It was found later that this belief was amply justified.
Of course, this did not, in any way, eliminate the need to
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explain the program to the
workers in advance. On the contrary, since
this study was to be undertaken for a group of white collar workers,
it was emphasized that effort should be made to clear their doubts, if
any.
Other possible sources of bias in the design of the plan are the
precise definition of the population to be sampled, the definition of
the different states of activity, and the method of selecting the
observation times.
It should be noted here that, even within a department, different
workers were not supposed to be performing the same type of work, in
the sense that they were assigned different duties. Thus, a single
universe, in this respect, cannot be rightly assumed. This makes the
data non-homogeneous and this characteristic will be further discussed
at a later stage. Some of the workers, whose duties approached those
of a supervisor, were not included in the population.
The breakdown of the work activity into the elements was detailed
enough to cover all the situation encountered. Again, the written
definition of activity-elements made it easy to identify, instantane-
ously, each element as it occurred. The continuous observations, at
regular intervals of one-half minute, made it further impossible for
the observer to introduce a bias, even unintentionally, by choosing
the moment of observation to coincide with any particular activity-
element.
In each department, the observer occupied an observation post
from where he could watch the activity of all the workers included in
the study. In fact, some of the workers were not included in the
study just because they were not observable all the time or part of
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the time. The constant presence
of the observer in the department did not seem to distract the attention of the
workers or hinder their work in any way.
Observations were made at all
times of the day, from 8 a.m. to 5 p.m., excepting the official rest periods. A
major difficulty in designing the plan was the scattered coffee breaks and
lunch breaks for different workers. This was taken care of, although not
completely, by not taking any observations at all or by taking fewer
observations on the coffee break groups, at one time or other. This procedure
resulted in an unequal number of observations on different workers.
A confidence level of 95 per cent
was adopted for the estimates of activity-elements as well as the element
groups, with the exceptions noted in the tables. In literature on work
sampling, this has been considered to represent typical estimation requirements
on delays, towards which the main attention of this study is directed. Most
authors further recommend that the number of observations be determined in
advance. In an industrial application of work sampling, this is a
"must," since the number of observations would directly determine the
cost of the study. This was no problem in the present study.
The formula for determining the
number of observations required, for a 95 per cent confidence level, is
where
S = desired accuracy
p = percentage occurrence of the activity-element being measured
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expressed as a percentage of the
total number of observations
N = number of observations
Of the two unknowns, S and p, p
is usually determined from a preliminary study of one day or so. S is the
accuracy requirement and depends upon the use to which the results of the study
will be put.
In many work sampling studies, a
relative accuracy of ±5% is termed acceptable, but this leads to abnormally
high requirements for the number of observations for different values of p. For
example, when p is 5%, N will become 30,400; and when p is 50%, N will be 1600.
To avoid this excessive
observations requirements, some people recommend an absolute error of ±2.5% or
±3%. In the present investigation, 1700 observations for department A (which
was the least number of all the departments) meets very well, the above requirements
of absolute accuracy.
In "Introduction to the
theory of work sampling" (p.5), it was mentioned that systematic sampling
is acceptable if no cyclic behavior is present in the phenomenon under study.
Clerical work is non-repetitive in nature; hence, the above condition is met.
Another condition is that the successive observations must be statistically
independent. According to this, a long delay, or, for that matter, any
activity-element should be counted only once, even though the formal sampling
schedule might require it to be observed several times. With as fine a
breakdown of activity elements as adopted in the present study,
Reference:
- A. J. Rowe, "Relative versus Absolute Errors
in Delay Measurements," Research Report No.24, University of
California, 1953, as reported by Ralph M. Barnes in "Work
Sampling," pp.20.
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Page No.: 14
there were few occasions when an
activity-element was longer than the average observation cycle of four minutes,
necessitating repeated observations; and to obtain the best estimates of the
delay percentages, all readings were recorded as often as they occurred,
although at the expense of some accuracy in the estimate of the standard error.
Since the purpose of the study
was not to set standards, the workers were not rated.
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DISCUSSION OF RESULTS
On the work sampling observation
sheet (see Appendix), fourteen work- and delay-activities are listed. Some of
these were further qualified with such suffixes as "a,"
"b," "w," and "p." It was assumed that this comprehensive
list would take care of most of the situations encountered during the actual
observation. With a few exceptions, this assumption did hold good in all the
departments.
For the purpose of analysis,
these activities are grouped into different "element groups" best
suited to bring out certain points of interest. The element groups under
consideration here are:
- Direct work activities (elements 1, 2, 3, 5,
8, 9, 13)
- Supporting delays (elements 4a, 6, 7w, 12)
- Personal delays (elements 7p, 11)
- Conversation-personal (element 4b)
Element group 2, "supporting
delays," has been termed in time-study literature as "unavoidable
delays," meaning delays associated with the work and beyond positive
control of the worker. The term, "unavoidable delays," has been
dropped from the present study in favor of the term, "supporting
delays," because of some evidence from the data that the so-called
"unavoidable delays" are partially within the control of the worker,
if only in a preventive sense. This aspect will be discussed later.
In some cases, in the
presentation of the results, element groups 3 and 4 have been combined to form
"delays within worker control" or "total personal delays."
Here again, the latter term is preferred since delays in connection with the
physiological needs are not within
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complete worker control. Element
4b (conversation-personal) has been,
in a few places, treated independently because, although originating
with the worker, it is not a personal (need) delay. At other times, it
has been included in "total personal delays" because of the belief
that
an increased amount of time spent on this element is an evidence of
increased fatigue. It must be understood though that there are no means
to substantiate this hypothesis, since a correlation with production
records is impossible.
Table 1 contains some significant
figures. The productive time,
which is an average of the direct work activities of all the workers of
a department for all the days, varied from 61.6% to 80.4%; the supporting
delays from 12.15% to 31.3% and the total personal delays from 7.1% to
10.8%. One fact is too obvious to escape attention and that is the
amazing consistency of the total personal delays in the departments
A and B. The wide variations in the productive time and the supporting
delays could be attributed to the non-homogeneity of the population
from a functional as well as the procedural viewpoint. The relative
consistency of the personal delays shows that they are less influenced
by the operation. Charts 7 and 8 give further evidence of this effect.
One of the purposes of the
present investigation was to compare
the personal delays of the white collar workers with the personal and/or
fatigue allowances in the industrial operations. Time study writers
have recommended these allowances ranging from 2 to 20 per cent of the
total work time. For example, Barnes¹ recommends a personal allowance
of 2 to 5 per cent per day for an average worker and believes that
"fatigue is of such little consequence in some kinds of work that no
Footnote:
- Barnes, "Motion and Time Study," 4th
edition, pp. 385–386.
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allowance is required at all.”
Holmes¹ similarly recommends a fixed personal (need) delay allowance of 3 to 5
per cent of the available work time. Carroll² suggests that fatigue and
personal (need) delays should account for about 20 per cent of the total work
time in most industrial operations. Shumard³ allows 2.5 per cent personal
(need) delays for male workers and 4 per cent for female workers. Some of these
recommendations are based on all-day time studies of various classes of work;
others have an essentially evaluative nature. The unscientific way in which
time study writers have approached this problem of personal and fatigue
allowances is summed up by Davidson⁴ as, “Fatigue allowances in contemporary
time study might be generally characterized as: a heterogeneous collection of
compensations for a number of different, not-too-well-defined natural effect,
as well as for mistakes in time study procedures; difficult to determine in
accord with objective criteria; and for which no adequate measure of ‘correctness’
exist.”
In the present study, an effort
was made to determine what is, rather than what ought to be, the time spent on
personal delays. The average of the four departments for total personal delays
is 8.14 per cent. To this must be added the time of two official rest periods
of 15 minutes each.
References
- Holmes, Applied Time and Motion Study, p.180
- Carroll, Time Study For Cost Control,
pp.98–100
- Shumard, A Primer of Time Study, pp.242–245
- Davidson, Functions and Bases of Time Standards,
p.181
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Thus, the total amount comes to
(8.14 + 6.25) = 14.39 per cent of the working time.
During the course of the
investigation, it was noticed that, quite frequently, the official rest periods
averaged 20 minutes each. On this basis, the total time spent on personal
delays would be (8.14 + 8.33) = 16.47 per cent of the working hours.
Table 1 also contains figures on
absolute accuracies with which the estimates on element groups were made. In
the design of the sampling plan, the accuracy requirements were set at ± 2.5%.
The highest figure reported in Table 1 (±2.15% for department D) is well within
the limit set above.
Referring to Tables 2 and 3 in
the departments A and B, definite trends of increasing absolute and relative
consistency (decreasing standard deviation s, and the coefficient of variation
s/p respectively) in all the element groups were found as the study progressed
from the first day to the last. The trend in departments C and D is not quite
discernible but it is believed that, with a larger amount of data, it would
have been more pronounced. It is not possible to assign definite causes to this
effect, but it may be conjectured that the group consistency bears some
relation with the period of the week, since, in all but one department, the
study was begun either on Monday or Tuesday and ended on Friday. Another guess
would be the group-consciousness of the presence of the observer.
A few common characteristics of
the data shall be discussed here. For the same worker, as the mean time (p̄)
increases from one element group to another, the absolute consistency
decreases, as evidenced by increasing standard deviation (s) estimates shown in
Tables 7a and 7b.
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These Tables further show that,
for the same worker, as the mean-time (p̄) increases from one element group to
another, the relative consistency increases as evidenced by the decreasing
coefficient-of-variation (s/p̄) estimates. The above characteristics were
expected as a feature of the statistical analysis. A further proof of this
phenomenon is contained in Tables 4, 5, and 6. Different workers in the same
department show a definite trend of increasing absolute consistency (decreasing
s) with increase in level (p̄), in case of element group "direct
work." Similar trends of decreasing consistency (increasing s), with
increase in level (p̄), are found in the element groups "supporting
delays" and "personal delays." The reason behind above trends is
that, in any statistical measurement, the variation will be maximum when p =
50% and will tend to decrease for the extreme values of p.
Table 7 was also arranged to
bring out the relationship, if any, between the length of experience and the
amount of productive and non-productive activities. No direct relationship was
found.
Table 9 shows the relationship
between the work experience and the total personal delays. Although no direct
correlation exists, it is interesting to note that workers with the same length
of experience in different departments differ widely in their delay
percentages. It will be further observed that this difference increases with an
increase in the length of experience. In absence of further supporting
evidence, this effect is believed to be a chance occurrence. A look at Table 8
reveals that, within each department, workers vary substantially in their
personal delays and that the range of variation is about the same for
departments A, B, and C.
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Table 10 and Chart 9 show the
relationship between the supporting delays and the total personal delays. Each
point on the chart represents the total personal delays and the total
supporting delays for a worker, for the entire observation period. In the chart,
there is some evidence of tendency for higher personal delays to be associated
with higher supporting delays. With the limited amount of data, no statistical
significance can be attached to this trend, but if personal delays can be
considered to be within worker control, the so-called "unavoidable
delays" too may be partially within the control of the worker.
Abruzzi writes that, "Apparently
unavoidable delays are partially within the control of the worker, but only in
a preventive sense. The occurrence of unavoidable delays cannot easily be
traced to the worker, but a reduced incidence of unavoidable delays can."
Since the concept of control
chart has been extensively used in the presentation of the data, an explanation
about the derivation of the control limits seems appropriate. For example, in
Table 11b, the average value for the element group in question, for the 3rd
day, for the six workers observed, is 22.0%. The total number of
observations for that day is 654. Then the daily limits would be:
📊 Control Limit
Calculations
Upper Control Limit (UCL):
UCL = p + 2 √( p(1 − p) / n )
= 0.22 + 2 √( 0.22(1 − 0.22) / 654 )
= 29.94%
Lower Control Limit (LCL):
LCL = 0.22 − 2 √( 0.22(1 − 0.22) / 654 )
= 14.06%
- Abruzzi, "Work, Workers, and Work
Measurement," p.110
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Text Content:
…and the central line would be
22.0%.
The worker limits are obtained as
follows:
In Table 11b, worker
"a" has been observed for four days. The total number of observations
for that worker for four days is 298. The average value for the element group
in question for worker "a," for the four days observed, is 30.5%.
Then the worker limits would be
Upper Control Limit (UCL) = p + 2
√[p(1 − p) / n]
= 0.305 + 2 √[0.305(1 − 0.305) / 298]
= 40.62%
Lower Control Limit (LCL) = 0.305
− 2 √[0.305(1 − 0.305) / 298]
= 19.38%
…and the central line would be
30.5%.
The control limits in Table 15
are obtained as follows:
In Table 15a for department A,
the grand average (p̄) for the element group in question is 74.0%. This grand
average, which is an average of all the workers in that department over all the
days they were observed, can be obtained from Table 11a. The grand average is
found to be 73.5%. For calculations of control limits, the grand average is
taken as 74.0%.
Next from Table 11a for
department A, the total number of observations for the 1st day was found to be
150. Then the control limits for the 1st day would be
Upper Control Limit (UCL) = p̄ +
2 √[p̄(1 − p̄) / n]
File:
parekh_1958_3429602_Page_25.png
= 81.16%
Lower Control Limit (LCL)
= 66.84%
and the central line would be 74.0%.
For calculation of the control limits for the 2nd day, p̂ would remain
unaltered; but the value of "n" would change to 412,
the total number of observations for the 2nd day for department A, again
obtained from Table 11a. In this manner, the control limits for all the days
for all the departments for all the element groups are calculated.
Table 14e summarizes the data
presented in Tables 11–12–13–14 (a, b, c, d). This condensation of data leads
to an important finding. It will be observed that, in general, there are more
points lying beyond daily-limits (all workers) than there are beyond
worker-limits (all days). In departments A and B, this ratio for the total
number of points is approximately 3 to 1, while in departments C and D,
it is approximately 1.5 to 1. On the whole, there is some evidence to
believe that the individual workers have more stable work patterns than the
groups. This is because the differences in level of the productive times of the
workers are great. This fact is important, in view of the common false
assumption in many time studies that daily variability and the variability
among the different workers is negligible. According to Cote,¹ "the use of
binomial formula alone to compute the accuracy …"
Reference:
- L. J. Cote and B. J. Scott,
"Comparison of All-day Time Study with Work Sampling by Use of Analysis of Variance,"
Journal of Industrial Engineering, Jan.–Feb. 1956, Vol. VII, No. 1.
File:
parekh_1958_3429602_Page_26.png
Page No.: 23
level obtained in a work sampling
program ignores sources of error
of larger magnitude, namely the variation among men, and the day-to-
day variation of the men." It must be admitted here that the results
of the present study are subject to the above mentioned limitations.
Analysis of variance was not applicable because of unequal number of
observations on different workers and the functional non-homogeneity
of the population.
Although not directly concerned with the present study, it would
be interesting to examine from closer quarters this problem of
variability among workers. Abruzzi¹ considers it to be an outcome of
the purposive behavior (of the workers) "which has an individualistic
and varying component, as well as an expected and relatively constant
component ...... this component ... shows up in terms of a common
level of (cycle-time) consistency among the workers in a group......
On the other hand, the individualistic and varying component shows
up as widely varying mean (cycle) times for workers in a group and
as stable mean (cycle) times for individual workers. This component
can be considered a reflection of the planning activities of individual
workers." Abruzzi's hypothesis is based on data gathered on jobs
of repetitive nature and performed with standardized methods by groups
of industrial operators. The present situation was totally different,
nevertheless his comments are enlightening.
Table 16 shows the number of points for each worker, for each
element group, that either lie above or below the 2s limits. A
further examination of the table shows that, of the total, about
1. Abruzzi, "Work, Workers,
and Work Measurement," pp. 245–250
File:
parekh_1958_3429602_Page_27.png
Page No.: 24
Equal number of points lie above
and below the limits for element group “direct work” in all departments but B.
In general, whenever more points (total or for each worker) are lying above UCL
than below LCL, for element group “direct work,” an opposite effect is visible
in the other three element groups, as would be expected. Analysis of data
presented in this table further establishes that, with the exception of
department B, the variability among workers is considerable. The reason behind
a great number of points beyond control limits is that these limits are based
on grand averages of pooled data on all workers.
Tables 17 through 20 show the
daily percentages and the cumulative percentages for each element. The element
groups shown here differ from those previously described, and are formed as
follows:
- Productive (elements 1, 2, 3, 5, 9, 13)
- Absent (elements 7w, 7p)
- Delay (elements 4a, 4b, 6, 8, 12, 14)
The above reformation of element
groups was deemed necessary, in view of the fact that, in some of the
departments, element 7w constituted a significant percentage of the supporting
delays. Again, absence of a worker from the department, in connection with the
work, cannot be branded entirely as a delay. Thus, the element group “delay”
here presents a different perspective of the total personal and non-personal
delays within a department, unaffected by the element 7w, which has a dubious
character.
Charts 1 through 4 show the
frequency distributions of the daily percentages of all the workers in all the
departments, for the different element groups. The distributions are far from
being normal, for several reasons. As mentioned earlier, the samples representing
File:
parekh_1958_3429602_Page_28.png
the daily percentages cannot be
considered to have been drawn from a single homogeneous universe. Again, errors
of sampling could alter the distribution to a considerable extent. These errors
are,
- Sampling errors (errors of observation)
- Process variation
(a) Differences from time-period to time-period.
(b) Differences from worker to worker.
(c) Residual (but real) process variations.
Another important factor
regarding the shape of the distribution is the sample size. Davidson¹ has shown
how radically the shape of a small sample size distribution can differ from
that of another small sample size distribution, both samples drawn from a known
universe which is normally distributed. Regarding random sampling errors,
Davidson writes, "The effects of sampling fluctuations are such that if we
continued sampling from our model of a normal universe we would by chance alone
obtain samples illustrating all five of the 'typical' curves." The five
typical curves are (A) symmetrical (B) positively skewed (C) negatively skewed
(D) rectangular and (E) bimodal.
According to Correll,² "The
reliability may be evaluated by comparison of two or more ratio-delay studies
taken on the same subject under similar conditions. If the results agree
closely, the coefficient of reliability is high." The scope of the present
investigation did not allow taking two independent studies in each department;
but in department A, an independent check study of 4 days was conducted,
- Davidson, "Functions and Bases of Time
Standards," pp. 200–204
- D. S. Correll and Ralph Barnes, "Industrial
Application of the Ratio-Delay Method," Advanced Management,
Aug.–Sept., 1950
File:
parekh_1958_3429602_Page_29.png
Page No.: 26
which included the same workers
and was carried out under essentially similar conditions as the main study. The
scheme of systematic sampling consisted of trips at regular intervals with
continuous observations as before. The results of the two studies are compared
below:
Comparison Table
|
Element groups |
Main Study (p̄) |
Check Study (p̄) |
|
1. Direct work |
73.5 |
75.6 |
|
2. Supporting delays |
19.3 |
17.9 |
|
3. Personal delays |
3.91 |
3.47 |
|
4. Conversation-personal |
3.29 |
3.03 |
No. of observations
- Main Study: 1792
- Check Study: 626
The results of the two studies
are in excellent agreement in spite of the fact that the number of observations
for the main study is almost three times as great as that for the check study.
The obvious conclusion is that a high degree of reliability exists, subject to
a constant bias.
It would be only proper to
conclude this discussion with remarks by Abruzzi:
"It seems clear that a theory of work must recognize that some
(apparently) unproductive work activities are needed for optimal results. ...
It may be unwise, for example, not to have formal and involuntary rest periods,
but it may be even more unwise not to allow or even encourage informal and
voluntary rest periods. Standardized rest periods give worker groups the rest
they need to prevent the gross work method from becoming unstable; the informal
rest periods give"
Reference:
- Abruzzi, Work, Workers and Work Measurement,
p.256
File Name:
parekh_1958_3429602_Page_30.png
Page Number: 27
Extracted Text:
individual workers the rest they
need to prevent the more subtle
aspects of the work method from becoming unstable.
File:
parekh_1958_3429602_Page_31.png
Page Number: 28
Content:
SUMMARY OF DATA AND CALCULATIONS
File:
parekh_1958_3429602_Page_32.png
TABLE 1: Distribution of Work
Activities with Respective Absolute Accuracies
|
Dept. |
Direct Work (p̄) |
Ab. Acc. |
Supporting Delays (p̄) |
Ab. Acc. |
Personal Delays (p̄) |
Conversation–Personal (p̄) |
Ab. Acc. |
No. of Days |
No. of Obs. |
|
Dept. A |
73.5 |
±2.08% |
19.3 |
±1.85% |
7.20 |
(3.91, 3.29) |
±1.22% |
4 |
1792 |
|
Dept. B |
80.4 |
±1.65% |
12.15 |
±1.34% |
7.45 |
(5.13, 2.32) |
±1.09% |
4 |
2338 |
|
Dept. C |
69.2 |
±1.42% |
20.0 |
±1.23% |
10.8 |
(5.94, 4.86) |
±0.98% |
7 |
4194 |
|
Dept. D |
61.6 |
±2.15% |
31.3 |
±2.05% |
7.10 |
(4.85, 2.25) |
±1.14% |
5 |
2021 |
File:
parekh_1958_3429602_Page_33.png
TABLE 2. AVERAGES (p) AND
STANDARD DEVIATIONS (s) FOR THE ELEMENT GROUPS
Element Group: Direct Work |
Supporting Delays | Personal Delays
Dept. A
|
Day |
Direct Work (p) |
s |
Supporting Delays (p) |
s |
Personal Delays (p) |
s |
|
1st |
82 |
7.69 |
12 |
6.5 |
4.7 |
4.23 |
|
2nd |
68 |
5.14 |
22 |
4.56 |
4.3 |
2.23 |
|
3rd |
71 |
4.35 |
22 |
3.97 |
3.8 |
1.83 |
|
4th |
77 |
3.93 |
16 |
3.74 |
3.5 |
1.87 |
Dept. B
|
Day |
Direct Work (p) |
s |
Supporting Delays (p) |
s |
Personal Delays (p) |
s |
|
1st |
82 |
6.40 |
10.7 |
5.15 |
5.1 |
3.67 |
|
2nd |
80 |
4.46 |
13.0 |
3.75 |
5.1 |
2.45 |
|
3rd |
83 |
3.95 |
10.6 |
3.23 |
4.9 |
2.26 |
|
4th |
78 |
3.67 |
13.3 |
3.01 |
5.4 |
2.01 |
Dept. C
|
Day |
Direct Work (p) |
s |
Supporting Delays (p) |
s |
Personal Delays (p) |
s |
|
1st |
62 |
6.32 |
30.0 |
5.98 |
5.6 |
3.03 |
|
2nd |
70 |
4.84 |
20.4 |
4.25 |
6.0 |
2.55 |
|
3rd |
78 |
4.25 |
13.8 |
3.54 |
5.0 |
2.23 |
|
4th |
66 |
5.32 |
21.2 |
4.60 |
6.0 |
2.72 |
|
5th |
68 |
5.50 |
19.7 |
4.67 |
5.8 |
2.79 |
|
6th |
69 |
5.54 |
20.0 |
5.10 |
6.3 |
3.13 |
|
7th |
69 |
5.53 |
18.6 |
4.89 |
6.8 |
3.17 |
Dept. D
|
Day |
Direct Work (p) |
s |
Supporting Delays (p) |
s |
Personal Delays (p) |
s |
|
1st |
55 |
7.42 |
40.0 |
7.27 |
3.2 |
2.62 |
|
2nd |
59 |
8.70 |
32.0 |
8.31 |
5.5 |
4.10 |
|
3rd |
60 |
5.50 |
34.0 |
5.34 |
4.7 |
2.38 |
|
4th |
61 |
5.20 |
29.5 |
4.85 |
6.0 |
2.57 |
|
5th |
74 |
6.50 |
21.0 |
6.07 |
3.8 |
2.85 |
File:
parekh_1958_3429602_Page_34.png
TABLE 3.
COEFFICIENTS-OF-VARIATION (s/p)
FOR THE ELEMENT GROUPS
|
Element Group |
Day |
Direct Work s/p (%) |
Supporting Delays s/p (%) |
Personal Delays s/p (%) |
Dept. A
|
Day |
Direct Work |
Supporting Delays |
Personal Delays |
|
1st |
9.39 |
54.2 |
90.1 |
|
2nd |
7.56 |
20.7 |
51.9 |
|
3rd |
6.13 |
18.0 |
48.1 |
|
4th |
5.11 |
23.4 |
53.4 |
Dept. B
|
Day |
Direct Work |
Supporting Delays |
Personal Delays |
|
1st |
7.81 |
48.2 |
72.0 |
|
2nd |
5.58 |
28.9 |
48.0 |
|
3rd |
4.76 |
30.5 |
46.1 |
|
4th |
4.70 |
22.6 |
37.2 |
Dept. C
|
Day |
Direct Work |
Supporting Delays |
Personal Delays |
|
1st |
10.20 |
19.95 |
54.2 |
|
2nd |
6.93 |
20.80 |
42.5 |
|
3rd |
5.45 |
25.60 |
44.6 |
|
4th |
8.06 |
21.70 |
45.3 |
|
5th |
8.09 |
23.70 |
48.1 |
|
6th |
8.04 |
25.50 |
49.7 |
|
7th |
8.03 |
26.30 |
46.6 |
Dept. D
|
Day |
Direct Work |
Supporting Delays |
Personal Delays |
|
1st |
13.50 |
18.15 |
82.0 |
|
2nd |
14.75 |
26.00 |
74.5 |
|
3rd |
9.17 |
15.72 |
50.6 |
|
4th |
8.53 |
16.45 |
42.8 |
|
5th |
8.79 |
28.90 |
75.0 |
File:
parekh_1958_3429602_Page_35.png
TABLE 14a. AVERAGES (p),
STANDARD DEVIATIONS (s)
AND COEFFICIENTS-OF-VARIATION (s/p) WITH p
ARRANGED IN DESCENDING ORDER OF MAGNITUDE.
Direct Work
|
Dept. |
Worker |
p |
s |
s/p |
|
A |
f |
90 |
3.0 |
3.33 |
|
e |
80 |
4.45 |
5.56 |
|
|
d |
78 |
4.68 |
6.00 |
|
|
b |
75 |
4.93 |
6.58 |
|
|
a |
64 |
5.56 |
8.70 |
|
|
c |
57 |
5.50 |
9.65 |
|
Dept. |
Worker |
p |
s |
s/p |
|
B |
c |
89 |
3.39 |
3.81 |
|
d |
84 |
3.94 |
4.69 |
|
|
e |
84 |
4.41 |
5.25 |
|
|
a |
82 |
4.31 |
5.26 |
|
|
f |
81 |
4.30 |
5.31 |
|
|
g |
80 |
4.25 |
5.32 |
|
|
h |
72 |
5.70 |
7.92 |
|
|
b |
66 |
5.46 |
8.29 |
File:
parekh_1958_3429602_Page_36.png
TABLE 4b. AVERAGES (p),
STANDARD DEVIATION (s)
AND COEFFICIENTS OF VARIATION (s/p) WITH p
ARRANGED IN DESCENDING ORDER OF MAGNITUDE
Direct Work
|
Dept |
Worker |
p |
s |
s/p |
|
C |
e |
86 |
3.94 |
4.58 |
|
d |
82 |
4.80 |
5.85 |
|
|
j |
70 |
5.47 |
7.82 |
|
|
a |
67 |
5.40 |
8.06 |
|
|
h |
66 |
5.56 |
8.42 |
|
|
b |
65 |
5.60 |
8.62 |
|
|
c |
65 |
5.60 |
8.62 |
|
|
g |
63 |
5.50 |
8.74 |
|
|
f |
58 |
5.56 |
9.60 |
|
Dept |
Worker |
p |
s |
s/p |
|
D |
g |
75 |
5.50 |
7.34 |
|
c |
72 |
5.90 |
8.20 |
|
|
a |
70 |
6.00 |
8.57 |
|
|
b |
57 |
5.50 |
11.4 |
|
|
f |
56 |
6.57 |
11.7 |
|
|
d |
52 |
7.00 |
13.45 |
|
|
e |
47 |
6.40 |
13.60 |
File:
parekh_1958_3429602_Page_37.png
TABLE 5a. AVERAGES (p),
STANDARD DEVIATIONS (s)
AND COEFFICIENTS-OF-VARIATION (s/p) WITH p
ARRANGED IN DESCENDING ORDER OF MAGNITUDE.
Supporting Delays
|
Dept. |
Worker |
p |
s |
s/p |
Dept. A
|
Worker |
p |
s |
s/p |
|
c |
38 |
5.39 |
14.2 |
|
a |
30 |
5.31 |
17.7 |
|
e |
14 |
3.86 |
27.6 |
|
b |
13 |
3.83 |
29.4 |
|
d |
11 |
3.54 |
32.2 |
|
f |
5.5 |
2.30 |
41.8 |
Dept. B
|
Worker |
p |
s |
s/p |
|
h |
22.6 |
5.31 |
23.5 |
|
b |
22 |
4.78 |
21.7 |
|
a |
13.8 |
3.87 |
28.0 |
|
g |
11.0 |
3.32 |
30.2 |
|
d |
9.5 |
3.15 |
33.2 |
|
f |
8.8 |
3.11 |
35.3 |
|
e |
8.2 |
3.30 |
40.3 |
|
c |
7.3 |
2.82 |
38.6 |
File:
parekh_1958_3429602_Page_38.png
TABLE 5b. AVERAGES (p),
STANDARD DEVIATIONS (s)
AND COEFFICIENTS-OF-VARIATION (s/p) WITH p
ARRANGED IN DESCENDING ORDER OF MAGNITUDE.
Supporting Delays
|
Worker |
p |
s |
s/p |
Dept. C
|
Worker |
p |
s |
s/p |
|
f |
27.0 |
5.01 |
18.55 |
|
a |
26.0 |
5.03 |
19.35 |
|
h |
23.8 |
5.00 |
21.00 |
|
c |
23.6 |
5.00 |
21.20 |
|
b |
23.0 |
4.95 |
21.50 |
|
g |
21.0 |
4.65 |
22.10 |
|
j |
14.6 |
4.09 |
28.00 |
|
d |
11.5 |
3.99 |
34.70 |
|
e |
7.4 |
2.97 |
40.10 |
Dept. D
|
Worker |
p |
s |
s/p |
|
e |
49.5 |
6.43 |
13.0 |
|
d |
44.0 |
6.94 |
15.8 |
|
b |
39.0 |
6.39 |
16.4 |
|
a |
28.0 |
5.93 |
21.2 |
|
f |
21.0 |
5.40 |
25.70 |
|
c |
20.0 |
5.21 |
26.0 |
|
g |
18.0 |
4.92 |
27.30 |
File:
parekh_1958_3429602_Page_39.png
Page No.: 36
TABLE 6a. AVERAGES (p),
STANDARD DEVIATIONS (s) AND COEFFICIENTS-OF-VARIATION (s/p) WITH p ARRANGED IN
DESCENDING ORDER OF MAGNITUDE
Personal Delays
|
Worker |
p |
s |
s/p |
Dept. A
|
Worker |
p |
s |
s/p |
|
b |
7.5 |
3.0 |
40.0 |
|
d |
6.0 |
2.74 |
45.7 |
|
e |
5.0 |
2.42 |
48.4 |
|
a |
2.0 |
1.62 |
81.2 |
|
f |
2.0 |
1.40 |
70.0 |
|
c |
1.0 |
1.10 |
110.0 |
Dept. B
|
Worker |
p |
s |
s/p |
|
b |
9.0 |
3.31 |
36.8 |
|
e |
6.8 |
3.03 |
44.6 |
|
d |
6.0 |
2.60 |
43.4 |
|
f |
5.0 |
2.39 |
47.8 |
|
h |
4.8 |
2.71 |
56.7 |
|
g |
4.5 |
2.20 |
48.9 |
|
c |
3.0 |
1.85 |
61.7 |
|
a |
2.5 |
1.74 |
69.6 |
File:
parekh_1958_3429602_Page_40.png
Page No.: 37
TABLE 6b. AVERAGES (p),
STANDARD DEVIATIONS (s) AND COEFFICIENTS-OF-VARIATION (s/p), WITH p ARRANGED IN
DESCENDING ORDER OF MAGNITUDE
Personal Delays
|
Worker |
p |
s |
s/p |
Dept. C
|
Worker |
p |
s |
s/p |
|
c |
9.6 |
3.47 |
36.2 |
|
j |
9.0 |
3.42 |
38.0 |
|
f |
7.5 |
2.97 |
39.6 |
|
b |
7.4 |
3.08 |
41.6 |
|
g |
7.2 |
2.96 |
41.1 |
|
h |
4.5 |
2.46 |
54.7 |
|
d |
4.2 |
2.52 |
60.0 |
|
a |
3.8 |
2.18 |
57.4 |
|
e |
1.3 |
1.27 |
92.7 |
Dept. D
|
Worker |
p |
s |
s/p |
|
f |
20.0 |
5.3 |
26.5 |
|
g |
6.0 |
3.09 |
51.6 |
|
d |
1.9 |
1.9 |
100.0 |
|
c |
1.8 |
1.72 |
95.6 |
|
b |
1.4 |
1.52 |
108.5 |
|
e |
1.3 |
1.43 |
110.0 |
|
a |
0.7 |
— |
— |
File:
parekh_1958_3429602_Page_41
TABLE 7a
Averages (p), Standard
Deviations (s), and Coefficients of Variation (s/p) with the Workers Arranged
According to the Length of Experience
Dept. A
|
Worker |
Experience |
Direct Work (p) |
s |
s/p |
Supporting Delays (p) |
s |
s/p |
Personal Delays (p) |
s |
s/p |
|
b |
15 mo. |
75 |
4.93 |
6.58 |
13 |
3.83 |
29.4 |
7.5 |
3.0 |
40.0 |
|
f |
10 mo. |
90 |
3.0 |
3.33 |
5.5 |
2.3 |
41.8 |
2.0 |
1.4 |
70.0 |
|
c |
4 mo. |
57 |
5.5 |
9.65 |
38 |
5.39 |
14.2 |
1.0 |
1.1 |
110.0 |
|
e |
4 mo. |
80 |
4.45 |
5.56 |
14 |
3.86 |
27.6 |
5.0 |
2.42 |
48.4 |
|
a |
2 mo. |
64 |
5.56 |
8.70 |
30 |
5.31 |
17.7 |
2.0 |
1.62 |
81.2 |
|
d |
0 mo. |
78 |
4.68 |
6.00 |
11 |
3.54 |
32.2 |
6.0 |
2.74 |
45.7 |
Dept. B
|
Worker |
Experience |
Direct Work (p) |
s |
s/p |
Supporting Delays (p) |
s |
s/p |
Personal Delays (p) |
s |
s/p |
|
h |
52 mo. |
72 |
5.7 |
7.92 |
22.6 |
5.31 |
23.5 |
4.8 |
2.71 |
56.7 |
|
e |
48 mo. |
84 |
4.41 |
5.25 |
8.2 |
3.3 |
40.3 |
6.8 |
3.03 |
44.6 |
|
b |
19 mo. |
66 |
5.46 |
8.29 |
22 |
4.78 |
21.7 |
9.0 |
3.31 |
36.8 |
|
c |
10 mo. |
89 |
3.39 |
3.81 |
7.3 |
2.82 |
38.6 |
3.0 |
1.85 |
61.7 |
|
a |
4 mo. |
82 |
4.31 |
5.26 |
13.8 |
3.87 |
28.0 |
2.5 |
1.74 |
69.6 |
|
g |
3 mo. |
80 |
4.25 |
5.32 |
11.0 |
3.32 |
30.2 |
4.5 |
2.2 |
48.9 |
|
d |
3 mo. |
84 |
3.94 |
4.69 |
9.5 |
3.15 |
33.2 |
6.0 |
2.6 |
43.4 |
|
f |
1 mo. |
81 |
4.3 |
5.31 |
8.8 |
3.11 |
35.3 |
5.0 |
2.39 |
47.8 |
File:
parekh_1958_3429602_Page_42.png
Dept. C
|
Worker |
Experience |
Direct Work p |
s |
s/p |
Supporting Delays p |
s |
s/p |
Personal Delays p |
s |
s/p |
|
d |
28 yrs. |
82 |
4.8 |
5.85 |
11.5 |
3.99 |
34.7 |
4.2 |
2.52 |
60.0 |
|
h |
5 yrs. |
66 |
5.56 |
8.42 |
23.8 |
5.0 |
21.0 |
4.5 |
2.46 |
54.7 |
|
b |
3 yrs. |
65 |
5.6 |
8.62 |
23 |
4.95 |
21.5 |
7.4 |
3.08 |
41.6 |
|
a |
19 mo. |
67 |
5.4 |
8.06 |
26 |
5.03 |
19.35 |
3.8 |
2.18 |
57.4 |
|
g |
17 mo. |
63 |
5.5 |
8.74 |
21 |
4.65 |
22.1 |
7.2 |
2.96 |
41.1 |
|
j |
7 mo. |
70 |
5.47 |
7.82 |
14.6 |
4.09 |
28.0 |
9.0 |
3.42 |
38.0 |
|
f |
4 mo. |
58 |
5.56 |
9.60 |
27 |
5.01 |
18.55 |
7.5 |
2.97 |
39.6 |
|
c |
3 mo. |
65 |
5.6 |
8.62 |
23.6 |
5.0 |
21.2 |
9.6 |
3.47 |
36.2 |
|
e |
1 mo. |
86 |
3.94 |
4.58 |
7.4 |
2.97 |
40.1 |
1.3 |
1.27 |
92.7 |
Table Caption
TABLE 7b. Averages (p),
Standard Deviations (s), and Coefficients of Variation (s/p) with the workers
arranged according to the length of experience.
File:
parekh_1958_3429602_Page_43.png
Dept. D
|
Worker |
Experience |
Direct Work (p) |
s |
s/p |
Supporting Delays (p) |
s |
s/p |
Personal Delays (p) |
s |
s/p |
|
e |
14 yrs. |
47 |
6.4 |
13.6 |
49.5 |
6.43 |
13.0 |
1.3 |
1.43 |
110.0 |
|
g |
27 mo. |
75 |
5.5 |
7.34 |
18 |
4.92 |
27.3 |
6.0 |
3.09 |
51.6 |
|
d |
17 mo. |
52 |
7.0 |
13.45 |
44 |
6.94 |
15.8 |
1.9 |
1.9 |
100.0 |
|
f |
17 mo. |
56 |
6.57 |
11.7 |
21 |
5.4 |
25.7 |
20 |
5.3 |
26.5 |
|
a |
7 mo. |
70 |
6.0 |
8.57 |
28 |
5.93 |
21.2 |
0.7 |
— |
— |
|
b |
7 mo. |
57 |
6.5 |
11.4 |
39 |
6.39 |
16.4 |
1.4 |
1.52 |
108.5 |
|
c |
5 mo. |
72 |
5.9 |
8.2 |
20 |
5.21 |
26.0 |
1.8 |
1.72 |
95.6 |
Caption
TABLE 7c. Averages (p),
standard deviations (s) and coefficients-of-variation (s/p), with the workers
arranged according to the length of experience.
File:
parekh_1958_3429602_Page_44(3).png
Page No.: 42
TABLE 8. RELATION BETWEEN WORK
EXPERIENCE AND THE TOTAL PERSONAL DELAYS
Workers arranged in descending
order of experience in the respective departments.
Element Groups: (Personal Delays + Conversation-personal)
Dept. A
- b – 12.30
- f – 4.02
- c – 4.30
- e – 6.10
- a – 5.70
- d – 10.60
Dept. B
- h – 5.60
- e – 7.28
- b – 12.40
- c – 3.77
- a – 3.78
- g – 9.04
- d – 6.56
- f – 10.26
Dept. C
- d – 6.35
- h – 10.00
- b – 11.90
- a – 7.10
- g – 15.80
- j – 15.37
- f – 14.80
- c – 11.40
- e – 6.14
Dept. D
- e – 3.60
- g – 6.15
- d – 3.80
- f – 22.50
- a – 2.10
- b – 4.10
- c – 7.20
Summary
|
Metric |
Dept. A |
Dept. B |
Dept. C |
Dept. D |
|
Average |
7.17 |
7.33 |
10.98 |
7.06 |
|
Range |
8.28 |
8.63 |
9.66 |
20.40 |
File:
parekh_1958_3429602_Page_45.png
TABLE 9: Relation Between Work
Experience and the Total Personal Delays
|
Dept. |
Worker |
Present Experience |
Delay (l4 + 7p + lb) |
|
C |
d |
28 yrs. |
6.35 |
|
D |
e |
14 yrs. |
3.60 |
|
C |
h |
5 yrs. |
10.00 |
|
B |
h |
4 yrs. 2 mo. |
5.60 |
|
B |
e |
4 yrs. |
7.28 |
|
C |
b |
3 yrs. |
11.90 |
|
D |
g |
2 yrs. 3 mo. |
6.15 |
|
C |
a |
19 mo. |
7.10 |
|
B |
b |
19 mo. |
12.40 |
|
D |
d |
17 mo. |
3.80 |
|
C |
g |
17 mo. |
15.80 |
|
D |
f |
17 mo. |
22.50 |
|
A |
b |
15 mo. |
12.30 |
|
B |
c |
10 mo. |
3.77 |
|
A |
f |
10 mo. |
4.02 |
|
D |
a |
7 mo. |
2.10 |
|
D |
b |
7 mo. |
4.10 |
|
C |
j |
7 mo. |
15.37 |
File:
parekh_1958_3429602_Page_46.png
Page No.: 43
TABLE 9. (Continued)
RELATION BETWEEN WORK EXPERIENCE AND THE TOTAL PERSONAL DELAYS
|
Dept. |
Worker |
Present Experience |
Delay% (Dl + Tp + Lb) |
|
D |
c |
5 mo. |
7.20 |
|
B |
a |
4 mo. |
3.78 |
|
A |
c |
4 mo. |
4.30 |
|
A |
e |
4 mo. |
6.10 |
|
C |
f |
4 mo. |
14.80 |
|
B |
d |
3 mo. |
6.56 |
|
B |
g |
3 mo. |
9.04 |
|
C |
c |
3 mo. |
11.40 |
|
A |
a |
2 mo. |
5.70 |
|
C |
e |
1 mo. |
6.14 |
|
B |
f |
1 mo. |
10.26 |
|
A |
d |
0 mo. |
10.60 |
File:
parekh_1958_3429602_Page_47
TABLE 10a: Relation Between
Supporting Delays and Total Personal Delays
Dept. A
|
Worker |
Direct Work |
% |
Supporting Delays |
% |
Personal Delays |
% |
Conversation-other |
% |
Total No. Obs. |
|
f |
182 |
90.5 |
11 |
5.48 |
4 |
2.01 |
4 |
2.01 |
201 |
|
e |
260 |
80.3 |
44 |
13.6 |
16 |
4.94 |
4 |
1.16 |
324 |
|
d |
245 |
78.5 |
34 |
10.9 |
18 |
5.77 |
15 |
4.83 |
312 |
|
b |
230 |
74.7 |
40 |
13.0 |
23 |
7.47 |
15 |
4.83 |
308 |
|
a |
190 |
63.8 |
91 |
30.5 |
5 |
1.67 |
12 |
4.03 |
298 |
|
c |
186 |
57.4 |
124 |
38.3 |
3 |
0.9 |
11 |
3.4 |
324 |
Dept. B
|
Worker |
Direct Work |
% |
Supporting Delays |
% |
Personal Delays |
% |
Conversation-other |
% |
Total No. Obs. |
|
c |
303 |
88.9 |
25 |
7.33 |
10 |
2.93 |
3 |
0.84 |
341 |
|
e |
175 |
84.5 |
17 |
8.22 |
14 |
6.76 |
1 |
0.52 |
207 |
|
d |
290 |
83.9 |
33 |
9.54 |
21 |
6.07 |
2 |
0.49 |
346 |
|
a |
262 |
82.4 |
44 |
13.8 |
8 |
2.52 |
4 |
1.26 |
318 |
|
f |
269 |
81.0 |
29 |
8.74 |
17 |
5.13 |
17 |
5.13 |
332 |
|
g |
285 |
80.0 |
39 |
10.96 |
16 |
4.52 |
16 |
4.52 |
356 |
|
b |
206 |
65.6 |
69 |
22.0 |
28 |
8.92 |
11 |
3.48 |
314 |
File:
parekh_1958_3429602_Page_48.png
TABLE 10b. RELATION BETWEEN
THE SUPPORTING DELAYS AND THE TOTAL PERSONAL DELAYS
|
Worker |
Direct Work |
% |
Supporting Delays |
% |
Personal Delays |
% |
Conversation-other |
% |
Total No. Obs. |
|
Dept. C |
|||||||||
|
e |
470 |
86.5 |
40 |
7.36 |
7 |
1.34 |
26 |
4.8 |
543 |
|
d |
369 |
82.1 |
52 |
11.55 |
19 |
9.23 |
9 |
2.12 |
449 |
|
a |
356 |
66.8 |
139 |
26.1 |
20 |
3.75 |
18 |
3.35 |
533 |
|
b |
329 |
65.0 |
117 |
23.1 |
37 |
7.35 |
23 |
4.55 |
506 |
|
c |
330 |
65.0 |
120 |
23.6 |
49 |
9.64 |
9 |
1.76 |
508 |
|
g |
338 |
63.1 |
113 |
21.1 |
38 |
7.2 |
46 |
8.6 |
535 |
|
f |
320 |
58.3 |
148 |
26.9 |
41 |
7.46 |
40 |
7.34 |
549 |
|
Worker |
Direct Work |
% |
Supporting Delays |
% |
Personal Delays |
% |
Conversation-other |
% |
Total No. Obs. |
|
Dept. D |
|||||||||
|
g |
230 |
75.5 |
56 |
18.35 |
19 |
6.15 |
0 |
0 |
305 |
|
c |
214 |
72.5 |
60 |
20.3 |
5 |
1.77 |
16 |
5.43 |
295 |
|
a |
199 |
69.6 |
81 |
28.3 |
2 |
0.7 |
4 |
1.4 |
286 |
|
b |
165 |
56.7 |
114 |
39.2 |
4 |
1.37 |
8 |
2.73 |
291 |
|
f |
161 |
56.5 |
60 |
21.0 |
59 |
20.7 |
5 |
1.8 |
285 |
|
d |
134 |
52.4 |
112 |
43.8 |
5 |
1.9 |
5 |
1.9 |
256 |
|
e |
142 |
46.9 |
150 |
49.5 |
4 |
1.29 |
7 |
2.31 |
303 |
File:
parekh_1958_3429602_Page_49.png
Element Group: Direct Work
Department: A
Worker-wise Data
|
Worker |
1st |
2nd |
3rd |
4th |
UCL |
LCL |
Avg. for Worker |
No. Obs. |
|
a |
88.0 |
61.2 |
58.0 |
65.58 |
80.7 |
47.3 |
63.8 |
298 |
|
b |
88.0 |
68.28 |
69.5 |
82.3 |
89.8 |
60.2 |
74.7 |
308 |
|
c |
68.0 |
53.46 |
55.54 |
60.38 |
73.5 |
40.5 |
57.4 |
324 |
|
d |
76.0 |
76.75 |
75.16 |
84.37 |
92.1 |
63.9 |
78.5 |
312 |
|
e |
84.0 |
80.22 |
81.2 |
78.11 |
93.3 |
66.7 |
80.3 |
324 |
|
f |
— |
— |
88.54 |
92.71 |
99.0 |
81.0 |
90.5 |
201 |
|
g |
88.0 |
— |
— |
— |
— |
— |
88.0 |
25 |
Day-wise Summary
|
Metric |
1st |
2nd |
3rd |
4th |
|
Avg. for the Day |
82.0 |
68.25 |
71.2 |
77.3 |
|
UCL |
100.0 |
83.4 |
84.0 |
89.88 |
|
LCL |
58.5 |
52.6 |
58.0 |
64.12 |
|
No. Obs. |
150 |
412 |
654 |
576 |
Overall Summary
- Average (Overall): 73.5
- Total Observations: 1792
File:
parekh_1958_3429602_Page_50.png
Element Group: Supporting
Delays
Dept.: A
|
Worker |
1st |
2nd |
3rd |
4th |
UCL |
LCL |
Ave. for Worker |
No. of Obs. |
|
a |
4.0 |
30.6 |
37.2 |
30.26 |
40.62 |
19.38 |
30.5 |
298 |
|
b |
12.0 |
18.3 |
15.25 |
6.24 |
20.66 |
5.34 |
13.0 |
308 |
|
c |
28.0 |
38.4 |
41.9 |
36.5 |
48.78 |
27.22 |
38.3 |
324 |
|
d |
8.0 |
11.62 |
16.2 |
5.21 |
18.08 |
3.92 |
10.9 |
312 |
|
e |
12.0 |
12.8 |
13.68 |
14.6 |
21.72 |
6.28 |
13.6 |
324 |
|
f |
— |
— |
6.66 |
4.17 |
10.1 |
0.90 |
5.48 |
201 |
|
g |
8.0 |
— |
— |
— |
— |
— |
8.0 |
25 |
Daily Summary
|
Metric |
1st |
2nd |
3rd |
4th |
|
Average for the Day |
12.0 |
22.1 |
22.0 |
16.15 |
|
UCL |
25.0 |
31.12 |
29.94 |
23.48 |
|
LCL |
0.0 |
12.88 |
14.06 |
8.52 |
|
No. of Observations |
150 |
412 |
654 |
576 |
Overall Summary
- Average (Overall): 19.3
- Total Observations: 1792
File:
parekh_1958_3429602_Page_51.png
Element Group: Personal Delays
Dept. A
Worker-wise Data
|
Worker |
1st |
2nd |
3rd |
4th |
UCL (2s Limits) |
LCL |
Ave. for Worker |
No. Obs. |
|
a |
0.0 |
2.7 |
1.94 |
1.04 |
5.24 |
0.0 |
1.67 |
298 |
|
b |
0.0 |
7.32 |
9.53 |
7.30 |
13.5 |
1.5 |
7.47 |
308 |
|
c |
4.0 |
2.33 |
0.0 |
0.0 |
3.2 |
0.0 |
0.9 |
324 |
|
d |
16.0 |
4.65 |
4.76 |
5.21 |
11.48 |
0.52 |
5.77 |
312 |
|
e |
4.0 |
4.65 |
5.12 |
5.21 |
9.84 |
0.16 |
4.94 |
324 |
|
f |
--- |
--- |
1.94 |
2.08 |
4.80 |
0.0 |
2.01 |
201 |
|
g |
4.0 |
--- |
--- |
--- |
--- |
--- |
4.0 |
25 |
Day-wise Averages and Limits
|
Metric |
1st |
2nd |
3rd |
4th |
|
Ave. for the day |
4.66 |
4.31 |
3.82 |
3.47 |
|
UCL |
13.16 |
8.76 |
7.46 |
7.24 |
|
LCL |
0.0 |
0.0 |
0.14 |
0.0 |
|
No. Obs. |
150 |
412 |
654 |
576 |
Overall Summary
- Average for workers (overall): 3.91
- Total Observations: 1792
Footer Note
TABLE 11c. Averages for the
days and for the workers with daily percentages and control limits as shown.
File Name:
parekh_1958_3429602_Page_52.png
Element Group:
Conversation–personal
Dept.: A
Worker-wise Data
|
Worker |
1st |
2nd |
3rd |
4th |
UCL |
LCL |
Ave. for Worker |
No. Obs. |
|
a |
8.0 |
5.5 |
2.86 |
3.12 |
6.26 |
1.74 |
4.03 |
298 |
|
b |
0.0 |
6.1 |
5.72 |
4.17 |
7.24 |
2.36 |
4.83 |
308 |
|
c |
0.0 |
5.81 |
2.56 |
3.12 |
5.69 |
1.11 |
3.40 |
324 |
|
d |
0.0 |
6.98 |
3.88 |
5.21 |
7.22 |
2.38 |
4.83 |
312 |
|
e |
0.0 |
2.33 |
0.0 |
2.08 |
2.39 |
0.01 |
1.16 |
324 |
|
f |
— |
— |
2.86 |
1.04 |
3.98 |
0.02 |
2.01 |
201 |
|
g |
0.0 |
— |
— |
— |
— |
— |
0.0 |
25 |
Daily Averages and Control
Limits
|
Metric |
1st |
2nd |
3rd |
4th |
|
Ave. for the day |
1.34 |
5.34 |
2.98 |
3.06 |
|
UCL |
5.78 |
4.68 |
4.33 |
4.42 |
|
LCL |
0.22 |
1.32 |
1.67 |
1.58 |
|
No. Obs. |
150 |
412 |
654 |
576 |
Overall Summary
- Overall Average: 3.29
- Total Observations: 1792
Table Reference
TABLE 11A:
Averages for the days and for the workers with daily percentages and control
limits as shown.
File Name:
parekh_1958_3429602_Page_53.png
Element Group: Direct Work
Department: B
Worker-wise Data
|
Worker |
1st |
2nd |
3rd |
4th |
UCL |
LCL |
Avg. for Worker |
No. Obs. |
|
a |
83.85 |
87.2 |
82.0 |
79.1 |
94.93 |
69.07 |
82.4 |
318 |
|
b |
64.47 |
67.5 |
68.9 |
62.0 |
82.4 |
49.6 |
65.6 |
314 |
|
c |
86.85 |
96.16 |
88.7 |
85.4 |
99.17 |
78.83 |
88.9 |
341 |
|
d |
84.22 |
80.5 |
89.8 |
81.8 |
95.8 |
72.2 |
83.9 |
346 |
|
e |
84.22 |
83.75 |
85.4 |
— |
97.2 |
70.8 |
84.5 |
207 |
|
f |
89.48 |
80.0 |
85.4 |
76.0 |
93.9 |
68.1 |
81.0 |
332 |
|
g |
84.22 |
81.39 |
80.5 |
78.6 |
92.7 |
67.3 |
80.3 |
356 |
|
h |
88.96 |
68.58 |
— |
— |
89.1 |
54.9 |
71.8 |
124 |
Day-wise Summary
|
Metric |
1st |
2nd |
3rd |
4th |
|
Avg. for the Day |
82.5 |
80.5 |
82.7 |
77.6 |
|
UCL |
100.0 |
93.4 |
94.84 |
89.0 |
|
LCL |
62.8 |
66.6 |
71.16 |
67.0 |
|
No. Obs. |
290 |
645 |
634 |
769 |
Overall Summary
- Overall Average: 80.4
- Total Observations: 2338
Caption
TABLE 12a. Averages for the
days and for the workers with daily percentages and control limits as shown.
File:
parekh_1958_3429602_Page_54.png
Element Group: Supporting
Delays
Dept.: B
Worker-wise Data
|
Worker |
1st |
2nd |
3rd |
4th |
UCL |
LCL |
Ave. for Worker |
No. Obs. |
|
a |
16.15 |
11.52 |
15.72 |
13.33 |
21.54 |
6.06 |
13.82 |
318 |
|
b |
16.15 |
20.00 |
22.22 |
24.75 |
31.56 |
12.44 |
22.00 |
314 |
|
c |
5.26 |
2.56 |
6.82 |
10.95 |
12.94 |
1.66 |
7.33 |
341 |
|
d |
7.89 |
10.40 |
5.72 |
11.88 |
15.80 |
3.20 |
9.54 |
346 |
|
e |
10.52 |
10.00 |
5.60 |
— |
14.80 |
1.60 |
8.22 |
207 |
|
f |
7.89 |
12.50 |
6.75 |
8.00 |
15.02 |
2.58 |
8.74 |
332 |
|
g |
7.89 |
10.47 |
10.90 |
12.22 |
17.64 |
4.36 |
10.96 |
356 |
|
h |
15.78 |
25.60 |
— |
— |
33.22 |
11.98 |
22.60 |
124 |
Daily Averages and Control
Limits
|
Metric |
1st |
2nd |
3rd |
4th |
|
Average for the day |
10.7 |
13.0 |
10.57 |
13.26 |
|
UCL |
21.0 |
20.5 |
17.06 |
19.32 |
|
LCL |
0.40 |
5.50 |
4.14 |
7.28 |
|
No. of Observations |
290 |
645 |
634 |
769 |
Overall Summary
- Overall Average: 12.15
- Total Observations: 2338
Table Note
TABLE 12b: Averages for the
days and for the workers with daily percentages and control limits as shown.
File:
parekh_1958_3429602_Page_55.png
Element Group: Personal Delays
Dept.: B
Worker-wise Daily Data
|
Worker |
1st |
2nd |
3rd |
4th |
UCL (2s Limits) |
LCL |
Ave. for Worker |
No. Obs. |
|
a |
0.0 |
0.0 |
2.28 |
5.0 |
5.98 |
0.0 |
2.52 |
318 |
|
b |
9.69 |
11.25 |
7.78 |
7.95 |
15.62 |
2.38 |
8.92 |
214 |
|
c |
7.89 |
1.28 |
3.41 |
2.19 |
6.70 |
0.0 |
2.93 |
341 |
|
d |
7.89 |
7.80 |
3.41 |
6.32 |
11.2 |
0.8 |
6.07 |
346 |
|
e |
5.26 |
5.00 |
9.00 |
--- |
12.86 |
0.74 |
6.76 |
207 |
|
f |
2.63 |
5.00 |
5.60 |
5.60 |
9.78 |
0.22 |
5.13 |
332 |
|
g |
5.26 |
4.65 |
1.67 |
5.34 |
8.90 |
0.10 |
4.52 |
356 |
|
h |
2.63 |
5.82 |
--- |
--- |
10.22 |
0.0 |
4.84 |
124 |
Daily Averages & Control
Limits
|
Metric |
1st |
2nd |
3rd |
4th |
|
Average for the Day |
5.10 |
5.12 |
4.89 |
5.37 |
|
UCL |
12.44 |
10.0 |
9.42 |
9.42 |
|
LCL |
0.0 |
0.20 |
0.38 |
1.38 |
|
No. of Observations |
290 |
645 |
634 |
769 |
Overall Summary
- Overall Average: 5.13
- Total Observations: 2338
Caption
TABLE 12c: Averages for the
days and for the workers with daily percentages and control limits as shown.
File:
parekh_1958_3429602_Page_56.png
Element Group:
Conversation-personal
Department: B
Worker-wise Data
|
Worker |
1st |
2nd |
3rd |
4th |
UCL |
LCL |
Ave. for Worker |
No. Obs. |
|
a |
0.0 |
1.28 |
0.0 |
2.5 |
2.55 |
0.05 |
1.26 |
318 |
|
b |
9.69 |
1.25 |
1.1 |
5.3 |
5.86 |
1.14 |
3.48 |
314 |
|
c |
0.0 |
0.0 |
1.07 |
1.46 |
1.83 |
0.00 |
0.84 |
341 |
|
d |
0.0 |
1.3 |
1.07 |
0.0 |
1.04 |
0.00 |
0.49 |
346 |
|
e |
0.0 |
1.25 |
0.0 |
--- |
1.20 |
0.00 |
0.52 |
207 |
|
f |
0.0 |
2.5 |
2.25 |
10.4 |
7.40 |
2.60 |
5.13 |
332 |
|
g |
2.63 |
3.49 |
6.93 |
3.84 |
6.70 |
2.30 |
4.52 |
356 |
|
h |
2.63 |
0.0 |
--- |
--- |
2.09 |
0.00 |
0.76 |
124 |
Day-wise Averages and Limits
|
Metric |
1st |
2nd |
3rd |
4th |
|
Average for the Day |
1.70 |
1.38 |
1.84 |
3.77 |
|
UCL |
4.32 |
3.72 |
3.73 |
3.62 |
|
LCL |
0.68 |
1.28 |
1.27 |
1.38 |
|
No. Obs. |
290 |
645 |
634 |
769 |
Overall Summary
- Average (Overall): 2.32
- Total Observations: 2338
Caption
TABLE 12d. Averages for the
days and for the workers with daily percentages and control limits as shown.
File:
parekh_1958_3429602_Page_57.png
Element Group: Direct Work
Dept.: C
Worker-wise Data
|
Worker |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
UCL |
LCL |
No. Obs. |
Avg. for Worker |
|
a |
47.6 |
69.3 |
74.75 |
56.4 |
67.1 |
67.8 |
81.0 |
83.2 |
50.8 |
533 |
66.8 |
|
b |
55.0 |
66.7 |
74.25 |
66.3 |
60.5 |
77.8 |
45.2 |
81.85 |
48.15 |
506 |
65.0 |
|
c |
63.75 |
73.0 |
82.0 |
53.8 |
57.5 |
69.4 |
53.8 |
81.85 |
48.15 |
508 |
65.0 |
|
d |
81.0 |
82.0 |
85.9 |
87.7 |
80.4 |
69.0 |
86.8 |
96.4 |
67.6 |
449 |
82.1 |
|
e |
96.9 |
84.4 |
96.0 |
85.0 |
83.0 |
66.7 |
89.4 |
97.8 |
74.2 |
543 |
86.5 |
|
f |
47.9 |
50.5 |
74.8 |
62.0 |
59.7 |
65.0 |
41.3 |
74.7 |
41.3 |
549 |
58.3 |
|
g |
50.0 |
62.4 |
60.8 |
60.5 |
72.5 |
68.4 |
69.7 |
79.55 |
46.45 |
535 |
63.1 |
|
h |
— |
— |
— |
63.0 |
72.0 |
63.3 |
66.6 |
82.7 |
49.3 |
290 |
66.2 |
|
j |
— |
— |
— |
66.25 |
59.0 |
71.7 |
85.1 |
86.45 |
53.55 |
280 |
70.0 |
Daily Averages
|
Day |
Avg |
UCL |
LCL |
No. Obs. |
|
1st |
62.5 |
81.0 |
43.0 |
410 |
|
2nd |
69.6 |
84.53 |
55.47 |
628 |
|
3rd |
78.2 |
90.73 |
65.27 |
667 |
|
4th |
66.4 |
82.0 |
50.0 |
713 |
|
5th |
67.75 |
84.5 |
51.5 |
649 |
|
6th |
68.8 |
86.7 |
51.3 |
556 |
|
7th |
68.8 |
86.4 |
51.6 |
571 |
Overall Summary
- Total Observations: 4194
- Overall Average: 69.2
Footnote
TABLE 13a. Averages for the
days and for the workers with daily percentages and control limits as shown.
File:
parekh_1958_3429602_Page_58(1).png
Element Group: Supporting
Delays
Dept. C
|
Worker |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
UCL |
LCL |
No. Obs. |
Ave. for Worker |
|
a |
49.2 |
27.5 |
20.4 |
35.9 |
21.9 |
17.7 |
11.1 |
36.06 |
15.94 |
533 |
26.1 |
|
b |
45.0 |
25.5 |
18.5 |
22.9 |
22.5 |
12.7 |
24.2 |
32.9 |
13.1 |
506 |
23.1 |
|
c |
29.0 |
16.8 |
8.34 |
35.9 |
27.4 |
17.7 |
30.8 |
33.6 |
13.6 |
508 |
23.6 |
|
d |
11.9 |
12.8 |
9.79 |
9.23 |
11.4 |
19.0 |
7.55 |
19.5 |
3.5 |
449 |
11.55 |
|
e |
1.55 |
11.4 |
1.0 |
6.25 |
3.85 |
26.7 |
4.55 |
13.34 |
1.46 |
543 |
7.36 |
|
f |
34.8 |
26.4 |
15.1 |
23.0 |
31.2 |
23.8 |
41.3 |
37.0 |
17.0 |
549 |
26.9 |
|
g |
37.5 |
21.5 |
19.6 |
21.0 |
10.1 |
20.0 |
16.7 |
30.3 |
11.7 |
535 |
21.1 |
|
h |
--- |
--- |
--- |
19.8 |
20.0 |
29.4 |
27.3 |
33.8 |
13.8 |
290 |
23.8 |
|
j |
--- |
--- |
--- |
15.0 |
27.4 |
11.7 |
3.0 |
6.42 |
6.42 |
280 |
14.63 |
Averages and Control Limits
|
Metric |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
|
Average for the Day |
30.0 |
20.4 |
13.8 |
21.2 |
19.7 |
20.0 |
18.6 |
|
UCL |
41.96 |
28.9 |
20.88 |
30.4 |
29.0 |
30.2 |
28.1 |
|
LCL |
18.04 |
11.9 |
6.72 |
12.0 |
10.36 |
9.80 |
8.82 |
|
No. of Observations |
410 |
628 |
667 |
713 |
649 |
556 |
571 |
Overall Summary
- Total Observations: 4194
- Overall Average: 20.0
Footnote
TABLE 13b. Averages for the
days and for the workers with daily percentages and control limits as shown.
File:
parekh_1958_3429602_Page_59(3).png
Element Group: Personal Delays
(Dept. C)
|
Worker |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
UCL (2s) |
LCL |
No. Obs. |
Avg. for Worker |
|
a |
1.6 |
1.07 |
2.91 |
5.13 |
2.75 |
9.63 |
4.84 |
8.16 |
0.0 |
533 |
3.75 |
|
b |
0.0 |
7.8 |
5.14 |
7.20 |
8.50 |
9.50 |
11.2 |
13.56 |
1.14 |
506 |
7.35 |
|
c |
7.25 |
7.86 |
9.66 |
6.41 |
13.7 |
11.3 |
12.3 |
16.54 |
2.66 |
508 |
9.64 |
|
d |
2.40 |
3.90 |
2.15 |
3.07 |
4.92 |
8.62 |
5.65 |
9.24 |
0.0 |
449 |
4.23 |
|
e |
1.55 |
1.04 |
1.00 |
2.50 |
0.0 |
0.0 |
3.02 |
3.84 |
0.0 |
543 |
1.34 |
|
f |
12.97 |
11.0 |
6.01 |
4.60 |
3.9 |
4.85 |
9.53 |
13.44 |
1.56 |
549 |
7.46 |
|
g |
9.38 |
9.68 |
9.8 |
6.17 |
4.35 |
5.0 |
4.53 |
13.12 |
1.28 |
535 |
7.20 |
|
h |
— |
— |
— |
8.64 |
4.0 |
1.41 |
3.05 |
9.42 |
0.0 |
290 |
4.48 |
|
j |
— |
— |
— |
11.25 |
9.6 |
6.65 |
7.47 |
15.84 |
2.16 |
280 |
8.94 |
Averages for the Days
|
Day |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
|
Avg. |
5.61 |
6.05 |
4.95 |
6.09 |
5.75 |
6.30 |
6.84 |
Control Limits (by Day)
|
Day |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
|
UCL |
11.66 |
11.1 |
9.46 |
11.44 |
11.38 |
12.56 |
13.14 |
|
LCL |
0.0 |
0.90 |
0.54 |
0.56 |
0.22 |
0.04 |
0.46 |
Number of Observations (by
Day)
|
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
Total |
|
410 |
628 |
667 |
713 |
649 |
556 |
571 |
4194 |
Overall Average
5.94
Caption
TABLE 13c. Averages for the
days and for the workers with daily percentages and control limits as shown
File:
parekh_1958_3429602_Page_60.png
Dept. C — Element Group:
Conversation-personal
Worker-wise Data
|
Worker |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
UCL (2s) |
LCL |
No. Obs. |
Ave. for Worker |
|
a |
1.6 |
2.13 |
1.94 |
2.57 |
8.25 |
4.82 |
3.06 |
5.18 |
1.62 |
533 |
3.35 |
|
b |
0.0 |
0.0 |
2.06 |
3.6 |
8.5 |
0.0 |
19.4 |
6.34 |
2.66 |
506 |
4.55 |
|
c |
0.0 |
2.29 |
0.0 |
3.89 |
1.4 |
1.55 |
3.1 |
2.97 |
0.63 |
508 |
1.76 |
|
d |
4.7 |
1.3 |
2.15 |
0.0 |
3.23 |
3.38 |
0.0 |
3.32 |
0.68 |
449 |
2.12 |
|
e |
0.0 |
3.11 |
2.0 |
6.25 |
13.15 |
6.6 |
3.03 |
6.63 |
2.97 |
543 |
4.80 |
|
f |
4.33 |
12.1 |
4.04 |
10.4 |
5.2 |
6.35 |
7.87 |
9.52 |
5.08 |
549 |
7.34 |
|
g |
3.13 |
6.42 |
9.8 |
12.33 |
13.0 |
6.6 |
9.07 |
11.02 |
6.18 |
535 |
8.60 |
|
h |
— |
— |
— |
8.64 |
4.0 |
5.89 |
3.09 |
8.20 |
2.80 |
290 |
5.52 |
|
j |
— |
— |
— |
7.5 |
4.0 |
10.0 |
4.48 |
9.35 |
3.45 |
280 |
6.43 |
Averages for the Day
|
Metric |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
|
Ave. for the Day |
1.89 |
3.95 |
3.05 |
6.31 |
6.8 |
4.9 |
5.76 |
|
UCL |
7.15 |
6.74 |
6.69 |
6.63 |
6.71 |
6.85 |
6.82 |
|
LCL |
2.85 |
3.26 |
3.31 |
3.37 |
3.29 |
3.15 |
3.18 |
|
No. Obs. |
410 |
628 |
667 |
713 |
649 |
556 |
571 |
Overall Summary
- Total Observations: 4194
- Overall Average (for workers): 4.86
Table Reference
TABLE 13d.
Averages for the days and for the workers daily — percentages and control
limits as shown.
File:
parekh_1958_3429602_Page_61(1).png
Element Group: Direct Work
Department: D
Worker-wise Data (Daily
Percentages & Control Limits)
|
Worker |
1st |
2nd |
3rd |
4th |
5th |
UCL |
LCL |
Avg. for Worker |
No. Obs. |
|
a |
57.8 |
77.0 |
70.4 |
67.4 |
80.0 |
88.2 |
51.8 |
69.6 |
286 |
|
b |
54.4 |
31.6 |
58.8 |
55.4 |
71.1 |
76.5 |
37.5 |
56.7 |
291 |
|
c |
75.5 |
46.7 |
67.1 |
79.1 |
83.7 |
89.5 |
54.5 |
72.5 |
295 |
|
d |
47.0 |
53.4 |
44.9 |
59.0 |
60.0 |
73.0 |
31.0 |
52.4 |
256 |
|
e |
15.0 |
50.0 |
49.4 |
45.5 |
66.1 |
66.2 |
27.8 |
46.9 |
303 |
|
f |
71.1 |
80.5 |
45.7 |
43.2 |
65.25 |
75.7 |
36.3 |
56.5 |
285 |
|
g |
57.5 |
66.6 |
76.4 |
77.7 |
90.0 |
91.65 |
58.35 |
75.5 |
305 |
Day-wise Averages and Control
Limits
|
Metric |
1st |
2nd |
3rd |
4th |
5th |
|
Avg. for the Day |
54.75 |
59.1 |
59.8 |
61.1 |
74.4 |
|
UCL |
77.2 |
85.3 |
76.5 |
76.6 |
93.6 |
|
LCL |
32.8 |
32.7 |
43.4 |
45.4 |
54.4 |
|
No. of Observations |
314 |
220 |
552 |
620 |
315 |
Overall Average for Workers:
61.6
Year:
2021
Table Title:
TABLE 11a. Averages for the
days and for the workers with daily percentages and control limits as shown.
File:
parekh_1958_3429602_Page_62(2).png
Element Group: Supporting
Delays
Dept. D
Worker-wise Data
|
Worker |
1st |
2nd |
3rd |
4th |
5th |
UCL (2s) |
LCL |
Ave. for Worker |
No. Obs. |
|
a |
42.0 |
15.4 |
28.4 |
29.2 |
20.0 |
39.86 |
16.14 |
28.3 |
286 |
|
b |
43.5 |
61.6 |
35.0 |
40.4 |
26.7 |
51.78 |
26.22 |
39.2 |
291 |
|
c |
16.33 |
33.3 |
29.3 |
13.2 |
11.62 |
30.42 |
9.58 |
20.3 |
295 |
|
d |
53.0 |
40.0 |
52.2 |
33.3 |
40.0 |
57.88 |
30.12 |
43.8 |
256 |
|
e |
82.5 |
44.5 |
48.2 |
48.9 |
32.2 |
62.36 |
36.64 |
49.5 |
303 |
|
f |
8.9 |
5.5 |
27.15 |
29.5 |
19.6 |
31.8 |
10.2 |
21.0 |
285 |
|
g |
40.0 |
30.6 |
19.1 |
12.2 |
2.0 |
27.84 |
8.16 |
18.35 |
305 |
Day-wise Averages
|
Metric |
1st |
2nd |
3rd |
4th |
5th |
|
Ave. for the day |
40.4 |
32.3 |
33.7 |
29.5 |
20.9 |
|
UCL |
54.54 |
48.62 |
44.68 |
39.2 |
33.14 |
|
LCL |
25.46 |
15.38 |
23.32 |
19.8 |
8.86 |
|
No. Obs. |
314 |
220 |
552 |
620 |
315 |
Overall Total Observations:
2021
Table Note
TABLE 11b. Averages for the
days and for the workers with daily percentages and control limits as shown.
File Name:
parekh_1958_3429602_Page_63.png
Element Group: Personal Delays
Dept. D
|
Worker |
1st |
2nd |
3rd |
4th |
5th |
UCL (2s Limits) |
LCL |
Ave. for Worker |
No. Obs. |
|
a |
0.0 |
3.8 |
0.0 |
1.13 |
0.0 |
--- |
--- |
0.7 |
286 |
|
b |
2.1 |
2.5 |
2.5 |
1.05 |
0.0 |
4.44 |
0.0 |
1.37 |
291 |
|
c |
0.0 |
1.16 |
1.16 |
1.1 |
2.34 |
5.24 |
0.0 |
1.77 |
295 |
|
d |
0.0 |
1.45 |
1.45 |
3.85 |
0.0 |
5.70 |
0.0 |
1.9 |
256 |
|
e |
2.5 |
1.2 |
1.2 |
0.0 |
0.0 |
4.16 |
0.0 |
1.29 |
303 |
|
f |
15.55 |
24.3 |
24.3 |
26.2 |
15.15 |
30.6 |
9.4 |
20.7 |
285 |
|
g |
2.5 |
4.5 |
4.5 |
10.1 |
8.0 |
12.18 |
0.0 |
6.15 |
305 |
Averages and Control Limits
(Day-wise)
|
Metric |
1st |
2nd |
3rd |
4th |
5th |
|
Ave. for the day |
3.23 |
5.46 |
4.71 |
6.13 |
3.81 |
|
UCL |
8.44 |
13.7 |
9.46 |
11.14 |
9.50 |
|
LCL |
0.0 |
0.0 |
0.0 |
0.86 |
0.0 |
|
No. Obs. |
314 |
220 |
552 |
620 |
315 |
Overall Average (All Workers)
4.85
Total Observations
2021
Caption
TABLE 14c. Averages for the
days and for the workers with daily percentages and control limits as shown.
File:
parekh_1958_3429602_Page_64(2).png
Element Group:
Conversation-personal
Dept.: D
Worker-wise Data (Daily
Percentages & Control Limits)
|
Worker |
1st |
2nd |
3rd |
4th |
5th |
UCL (2s Limits) |
LCL |
Avg. for Worker |
No. Obs. |
|
a |
0.0 |
3.8 |
1.1 |
2.27 |
0.0 |
2.77 |
0.03 |
1.4 |
286 |
|
b |
0.0 |
3.8 |
3.7 |
3.15 |
2.2 |
4.73 |
0.87 |
2.73 |
291 |
|
c |
8.17 |
13.34 |
2.44 |
6.6 |
2.34 |
8.04 |
2.76 |
5.43 |
295 |
|
d |
0.0 |
3.3 |
1.45 |
3.85 |
0.0 |
3.60 |
0.20 |
1.9 |
256 |
|
e |
0.0 |
0.0 |
1.2 |
5.6 |
1.7 |
4.01 |
0.59 |
2.31 |
303 |
|
f |
4.45 |
0.0 |
2.85 |
1.1 |
0.0 |
3.36 |
0.24 |
1.8 |
285 |
|
g |
0.0 |
0.0 |
0.0 |
0.0 |
0.0 |
--- |
--- |
0.0 |
305 |
Averages for the Day
|
Day |
Average |
|
1st |
1.62 |
|
2nd |
3.14 |
|
3rd |
1.79 |
|
4th |
3.27 |
|
5th |
0.89 |
Overall Average: 2.25
Control Limits (Daily)
|
Day |
UCL |
LCL |
|
1st |
3.58 |
0.42 |
|
2nd |
3.89 |
0.11 |
|
3rd |
3.19 |
0.81 |
|
4th |
3.12 |
0.88 |
|
5th |
3.58 |
0.42 |
Number of Observations (Daily)
|
Day |
No. Obs. |
|
1st |
311 |
|
2nd |
228 |
|
3rd |
552 |
|
4th |
620 |
|
5th |
315 |
Total Observations: 2021
Caption
TABLE 14d. Averages for the
days and for the workers with daily percentages and control limits as shown.
File:
parekh_1958_3429602_Page_65.png
Element Group:
Dept. A — Points Beyond
|
Category |
Direct Work |
Supporting Delays |
Personal Delays |
Conversation Personal |
Total |
Out of |
|
Worker-Limits (All Days) |
0 |
1 |
3 |
7 |
11 |
92 |
|
Daily-Limits (All Workers) |
2 |
13 |
4 |
14 |
33 |
Dept. B
|
Category |
Direct Work |
Supporting Delays |
Personal Delays |
Conversation Personal |
Total |
Out of |
|
0 |
0 |
1 |
10 |
11 |
116 |
|
|
3 |
4 |
2 |
20 |
29 |
Dept. C
|
Category |
Direct Work |
Supporting Delays |
Personal Delays |
Conversation Personal |
Total |
Out of |
|
3 |
14 |
2 |
26 |
45 |
228 |
|
|
10 |
18 |
4 |
38 |
70 |
Dept. D
|
Category |
Direct Work |
Supporting Delays |
Personal Delays |
Conversation Personal |
Total |
Out of |
|
5 |
10 |
2 |
15 |
32 |
140 |
|
|
4 |
14 |
6 |
21 |
45 |
Footer Text:
TABLE 11e. POINTS
(REPRESENTING WORKERS' DAILY AVERAGES)
BEYOND CONTROL-LIMITS GIVEN IN TABLES 11-12-13-14 (a, b, c, d)
File:
parekh_1958_3429602_Page_66(2).png
Element Groups: Direct Work
Dept. A
p̄ = 74.0
|
Day |
UCL |
LCL |
|
1st |
*81.16 |
66.84 |
|
2nd |
77.32 |
69.68* |
|
3rd |
77.43 |
70.57 |
|
4th |
77.66 |
70.34 |
Dept. B
p̄ = 80.0
|
Day |
UCL |
LCL |
|
1st |
84.70 |
75.30 |
|
2nd |
83.15 |
76.85 |
|
3rd |
83.17 |
76.83 |
|
4th |
82.88 |
77.12 |
Dept. C
p̄ = 69.0
|
Day |
UCL |
LCL |
|
1st |
73.57 |
64.43* |
|
2nd |
72.69 |
65.31 |
|
3rd |
*72.58 |
65.42 |
|
4th |
72.46 |
65.54 |
|
5th |
72.62 |
65.38 |
|
6th |
72.92 |
65.08 |
|
7th |
72.87 |
65.13 |
Dept. D
p̄ = 62.0
|
Day |
UCL |
LCL |
|
1st |
67.46 |
56.54* |
|
2nd |
68.55 |
55.45 |
|
3rd |
66.14 |
57.86 |
|
4th |
65.90 |
58.10 |
|
5th |
*67.46 |
56.54 |
95% Confidence Level
TABLE 15a.
Control Limits, based on grand averages (p̄) and total number of
observations for the day.
* Point beyond limit, on
the side indicated.
File:
parekh_1958_3429602_Page_67(1).png
Element Group: Supporting
Delays
Dept. A (p̄ = 19.0)
|
Day |
UCL |
LCL |
|
1st |
26.04 |
11.96 |
|
2nd |
22.86 |
15.14 |
|
3rd |
22.06 |
15.94 |
|
4th |
22.27 |
15.73 |
Dept. B (p̄ = 12.0)
|
Day |
UCL |
LCL |
|
1st |
15.82 |
8.18 |
|
2nd |
14.56 |
9.44 |
|
3rd |
14.58 |
9.42 |
|
4th |
14.34 |
9.66 |
Dept. C (p̄ = 20.0)
|
Day |
UCL |
LCL |
|
1st |
*23.95 |
16.05 |
|
2nd |
23.19 |
16.81 |
|
3rd |
23.10 |
*16.9 |
|
4th |
23.00 |
17.00 |
|
5th |
23.14 |
16.86 |
|
6th |
23.39 |
16.61 |
|
7th |
23.34 |
16.66 |
Dept. D (p̄ = 31.0)
|
Day |
UCL |
LCL |
|
1st |
*36.5 |
25.5 |
|
2nd |
37.57 |
24.43 |
|
3rd |
35.16 |
26.84 |
|
4th |
34.92 |
27.08 |
|
5th |
36.5 |
*25.5 |
Additional Notes
- Confidence Level: 95%
- Table Reference:
TABLE 15b: Control limits based on grand averages (p̄) and total number of observations for the day. - Footnote:
* Point beyond limit, on the side indicated.
File:
parekh_1958_3429602_Page_68.png
Element Group: Personal Delays
Dept. A (p̄ = 4.0)
|
Day |
UCL |
LCL |
|
1st |
7.20 |
0.80 |
|
2nd |
5.93 |
2.07 |
|
3rd |
5.53 |
2.47 |
|
4th |
5.63 |
2.37 |
Dept. B (p̄ = 5.5)
|
Day |
UCL |
LCL |
|
1st |
8.20 |
2.80 |
|
2nd |
7.31 |
3.69 |
|
3rd |
7.32 |
3.68 |
|
4th |
7.16 |
3.84 |
Dept. C (p̄ = 6.0)
|
Day |
UCL |
LCL |
|
1st |
8.39 |
3.61 |
|
2nd |
7.93 |
4.07 |
|
3rd |
7.87 |
4.13 |
|
4th |
7.81 |
4.19 |
|
5th |
7.89 |
4.11 |
|
6th |
8.05 |
3.95 |
|
7th |
8.02 |
3.98 |
Dept. D (p̄ = 5.0)
|
Day |
UCL |
LCL |
|
1st |
7.45 |
2.55 |
|
2nd |
7.94 |
2.06 |
|
3rd |
6.86 |
3.14 |
|
4th |
6.75 |
3.25 |
|
5th |
7.45 |
2.55 |
Additional Notes
- Confidence Level: 95%
- Table Reference:
TABLE 15c. CONTROL-LIMITS, BASED ON GRAND AVERAGES (p̄) AND TOTAL NUMBER OF OBSERVATIONS FOR THE DAY.
File:
parekh_1958_3429602_Page_69.png
Element Group:
Conversation-personal
Dept. A ( p̄ = 3.0 )
|
Day |
UCL |
LCL |
|
1st |
5.78 |
0.22 |
|
2nd |
*4.68 |
1.32 |
|
3rd |
4.33 |
1.67 |
|
4th |
4.42 |
1.58 |
Dept. B ( p̄ = 2.5 )
|
Day |
UCL |
LCL |
|
1st |
4.32 |
0.68 |
|
2nd |
3.72 |
1.28 |
|
3rd |
3.73 |
1.27 |
|
4th |
*3.62 |
1.38 |
Dept. C ( p̄ = 5.0 )
|
Day |
UCL |
LCL |
|
1st |
7.15 |
2.85* |
|
2nd |
6.74 |
3.26 |
|
3rd |
6.69 |
3.31* |
|
4th |
6.63 |
3.37 |
|
5th |
*6.71 |
3.29 |
|
6th |
6.85 |
3.15 |
|
7th |
6.82 |
3.18 |
Dept. D ( p̄ = 2.0 )
|
Day |
UCL |
LCL |
|
1st |
3.58 |
0.42 |
|
2nd |
3.89 |
0.11 |
|
3rd |
3.19 |
0.81 |
|
4th |
*3.12 |
0.88 |
|
5th |
3.58 |
0.42 |
Notes
- Confidence Level: 95%
- Table Reference: TABLE 15d
Control limits, based on grand averages (p̄) and total number of observations for the day. - * Point beyond limit, on the side indicated
File:
parekh_1958_3429602_Page_70.png
DEPT. A
95% Confidence Level
Element Group Analysis
|
Worker |
Total Points |
Direct Work Points (Above
UCL) |
Direct Work Points (Below
LCL) |
Supporting Delay Points
(Above UCL) |
Supporting Delay Points
(Below LCL) |
Personal Delay Points
(Above UCL) |
Personal Delay Points
(Below LCL) |
Conversation–Other Points
(Above UCL) |
Conversation–Other Points
(Below LCL) |
|
b |
4 |
2 |
2 |
– |
2 |
3 |
1 |
2 |
1 |
|
f |
2 |
2 |
– |
– |
2 |
– |
2 |
– |
1 |
|
c |
4 |
– |
3 |
4 |
– |
– |
2 |
1 |
1 |
|
e |
4 |
4 |
– |
– |
3 |
– |
– |
– |
2 |
|
a |
4 |
1 |
3 |
3 |
1 |
– |
3 |
2 |
– |
|
d |
4 |
1 |
– |
– |
3 |
1 |
– |
2 |
1 |
Totals
|
Category |
Above UCL |
Below LCL |
Total |
|
Direct Work Points |
10 |
8 |
18 |
|
Supporting Delay Points |
7 |
11 |
18 |
|
Personal Delay Points |
4 |
8 |
12 |
|
Conversation–Other Points |
7 |
6 |
13 |
Table Caption
TABLE 16a. POINTS
(REPRESENTING WORKERS' DAILY AVERAGES)
BEYOND FLUCTUATING CONTROL LIMITS, GIVEN IN TABLE 15
File:
parekh_1958_3429602_Page_71.png
DEPT. B
95% Confidence Level
Element Group
|
Worker |
Total Points |
Direct Work Points (Above
UCL) |
Direct Work Points (Below
LCL) |
Supporting Delay Points
(Above UCL) |
Supporting Delay Points
(Below LCL) |
Personal Delay Points
(Above UCL) |
Personal Delay Points
(Below LCL) |
Conversation–Other Points
(Above UCL) |
Conversation–Other Points
(Below UCL) |
|
h |
2 |
1 |
1 |
1 |
– |
– |
1 |
– |
1 |
|
e |
3 |
2 |
– |
– |
1 |
1 |
– |
– |
3 |
|
b |
4 |
– |
4 |
4 |
– |
4 |
– |
2 |
2 |
|
c |
4 |
4 |
– |
– |
3 |
– |
3 |
– |
3 |
|
a |
4 |
1 |
– |
2 |
– |
– |
3 |
– |
2 |
|
g |
4 |
– |
– |
– |
1 |
– |
1 |
2 |
– |
|
d |
4 |
1 |
– |
– |
2 |
1 |
1 |
– |
3 |
|
f |
4 |
2 |
1 |
– |
3 |
– |
1 |
1 |
1 |
Totals
- Direct Work Points: 11 (Above UCL) + 6 (Below
LCL) = 17
- Supporting Delay Points: 7 (Above UCL) + 10
(Below LCL) = 17
- Personal Delay Points: 6 (Above UCL) + 10 (Below
LCL) = 16
- Conversation–Other Points: 5 (Above UCL) + 15
(Below UCL) = 20
Table Reference
TABLE 16b. POINTS
(REPRESENTING WORKERS’ DAILY AVERAGES)
BEYOND FLUCTUATING CONTROL-LIMITS, GIVEN IN TABLE 15
File:
parekh_1958_3429602_Page_72(2).png
DEPT. C
95% Confidence Level
Table Structure
|
Worker |
Total Points |
Direct Work Points (Above
UCL) |
Direct Work Points (Below
LCL) |
Supporting Delays (Above
UCL) |
Supporting Delays (Below
LCL) |
Personal Delays (Above UCL) |
Personal Delays (Below LCL) |
Conversation–Other (Above
UCL) |
Conversation–Other (Below
LCL) |
|
d |
7 |
6 |
– |
– |
6 |
1 |
4 |
– |
5 |
|
h |
4 |
– |
2 |
2 |
– |
11 |
3 |
1 |
1 |
|
b |
7 |
2 |
3 |
3 |
1 |
3 |
1 |
2 |
4 |
|
a |
7 |
2 |
2 |
3 |
1 |
1 |
4 |
1 |
5 |
|
g |
7 |
– |
4 |
1 |
1 |
3 |
– |
4 |
– |
|
j |
4 |
1 |
1 |
1 |
3 |
2 |
– |
2 |
– |
|
f |
7 |
1 |
6 |
5 |
1 |
3 |
1 |
3 |
– |
|
c |
7 |
2 |
4 |
4 |
1 |
4 |
– |
– |
6 |
|
e |
7 |
6 |
– |
1 |
6 |
– |
7 |
1 |
4 |
Totals
- Direct Work Points:
- Above UCL = 20
- Below LCL = 22
- Total = 42
- Supporting Delays Points:
- Above UCL = 20
- Below LCL = 20
- Total = 40
- Personal Delays Points:
- Above UCL = 18
- Below LCL = 20
- Total = 38
- Conversation–Other Points:
- Above UCL = 14
- Below LCL = 25
- Total = 39
Footnote
TABLE 16c. Points
(representing workers’ daily averages) beyond fluctuating control-limits, given
in Table 15.
File:
parekh_1958_3429602_Page_73.png
DEPT. D
Element Group:
|
Worker |
Total Points |
Direct Work Points |
Supporting Delays Points |
Personal Delays Points |
Conversation–Other Points |
||||
|
Above UCL |
Below LCL |
Above UCL |
Below LCL |
Above UCL |
Below LCL |
Above UCL |
Below LCL |
||
|
e |
5 |
– |
4 |
4 |
– |
– |
4 |
1 |
2 |
|
g |
5 |
3 |
– |
1 |
2 |
2 |
1 |
– |
5 |
|
d |
5 |
– |
3 |
4 |
– |
– |
3 |
1 |
2 |
|
f |
5 |
2 |
2 |
– |
4 |
5 |
– |
1 |
2 |
|
a |
5 |
4 |
– |
1 |
2 |
– |
4 |
– |
2 |
|
b |
5 |
1 |
3 |
3 |
– |
– |
5 |
2 |
1 |
|
c |
5 |
4 |
1 |
– |
3 |
– |
4 |
3 |
– |
Totals
|
Category |
Above UCL |
Below LCL |
Total |
|
Direct Work |
14 |
13 |
27 |
|
Supporting Delays |
13 |
11 |
24 |
|
Personal Delays |
7 |
21 |
28 |
|
Conversation–Other |
8 |
14 |
22 |
Caption
TABLE 16d. Points
(representing workers' daily averages) beyond fluctuating control-limits, given
in Table 15.
File:
parekh_1958_3429602_Page_74.png
TABLE 17a. DAILY PERCENTAGES
Dept. A
|
Day |
1st |
2nd |
3rd |
4th |
Element Groups
|
Category |
1st |
2nd |
3rd |
4th |
|
Productive |
81.34 |
67.48 |
67.60 |
76.90 |
|
Absent |
2.67 |
8.25 |
13.10 |
5.73 |
|
Delay |
15.99 |
24.27 |
19.30 |
17.37 |
Elements
|
Element |
1st |
2nd |
3rd |
4th |
|
1 |
12.67 |
8.26 |
11.65 |
12.72 |
|
2 |
26.67 |
26.92 |
22.80 |
26.12 |
|
3 |
16.67 |
13.12 |
12.20 |
13.72 |
|
4a |
3.33 |
9.24 |
6.91 |
6.25 |
|
4b |
1.33 |
5.33 |
2.93 |
3.12 |
|
5 |
6.00 |
4.63 |
5.45 |
9.72 |
|
6 |
4.00 |
3.15 |
3.28 |
2.95 |
|
7 |
2.67 |
8.25 |
13.10 |
5.73 |
|
8 |
0.67 |
0.74 |
0.35 |
0.36 |
|
12 |
2.66 |
3.15 |
3.83 |
2.43 |
|
13 |
19.33 |
14.55 |
15.50 |
14.62 |
|
14 |
4.00 |
2.66 |
5.49 |
2.26 |
No. of Observations
|
1st |
2nd |
3rd |
4th |
|
150 |
412 |
— |
576 |
(Note: 3rd day observation
count not clearly visible in image)
File:
parekh_1958_3429602_Page_75.png
Page No.: 72
TABLE 17b. CUMULATIVE
PERCENTAGES
Dept. A
Days:
|
Category |
1 day |
2 days |
3 days |
4 days |
Element Groups
|
Group |
1 day |
2 days |
3 days |
4 days |
|
Productive |
81.34 |
71.23 |
69.42 |
71.94 |
|
Absent |
2.67 |
6.76 |
9.90 |
8.47 |
|
Delay |
15.99 |
22.01 |
20.68 |
19.59 |
Elements
|
Element |
1 day |
2 days |
3 days |
4 days |
|
1 |
12.67 |
9.45 |
10.54 |
11.25 |
|
2 |
26.67 |
26.90 |
24.85 |
25.22 |
|
3 |
16.67 |
14.10 |
13.15 |
13.32 |
|
4a |
3.33 |
7.66 |
7.30 |
6.94 |
|
4b |
1.33 |
4.27 |
3.60 |
3.44 |
|
5 |
6.00 |
4.98 |
5.23 |
6.82 |
|
6 |
4.00 |
3.38 |
3.33 |
3.23 |
|
7 |
2.67 |
6.76 |
9.90 |
8.47 |
|
8 |
0.67 |
0.70 |
0.51 |
0.47 |
|
12 |
2.66 |
3.00 |
3.42 |
3.08 |
|
13 |
19.33 |
15.80 |
15.65 |
15.33 |
|
14 |
4.00 |
3.00 |
2.52 |
2.43 |
No. of Observations
- 2 days: 562
- 3 days: 1111
- 4 days: 1687
File:
parekh_1958_3429602_Page_76.png
TABLE 18a. DAILY PERCENTAGES
Dept. B
Day:
1st 2nd 3rd 4th
Element Groups
|
Category |
1st |
2nd |
3rd |
4th |
|
Productive |
79.95 |
78.57 |
79.50 |
76.92 |
|
Absent |
2.41 |
2.80 |
3.37 |
1.30 |
|
Delays |
17.64 |
18.63 |
17.13 |
21.78 |
Elements
|
Element |
1st |
2nd |
3rd |
4th |
|
1 |
13.80 |
12.40 |
11.40 |
13.50 |
|
2 |
23.10 |
21.50 |
28.30 |
23.40 |
|
3 |
20.30 |
17.20 |
14.05 |
12.85 |
|
4a |
4.48 |
6.35 |
3.96 |
5.33 |
|
4b |
1.72 |
1.40 |
1.90 |
3.77 |
|
5 |
6.90 |
5.29 |
7.02 |
3.77 |
|
6 |
3.79 |
3.10 |
5.27 |
5.06 |
|
7 |
2.41 |
2.80 |
3.37 |
1.30 |
|
8 |
1.04 |
1.55 |
1.61 |
0.74 |
|
9 |
6.20 |
8.08 |
4.98 |
10.40 |
|
12 |
2.41 |
3.59 |
2.78 |
2.86 |
|
13 |
11.05 |
14.41 |
13.75 |
13.00 |
|
14 |
2.76 |
2.33 |
1.61 |
4.02 |
No. Obs.
|
1st |
2nd |
3rd |
4th |
|
290 |
615 |
683 |
769 |
File:
parekh_1958_3429602_Page_77.png
TABLE 18b. CUMULATIVE
PERCENTAGES
Dept. B
Days:
|
1 day |
2 days |
3 days |
4 days |
Element Groups
|
Category |
1 day |
2 days |
3 days |
4 days |
|
Productive |
79.95 |
79.03 |
79.60 |
78.70 |
|
Absent |
2.41 |
2.67 |
3.00 |
2.50 |
|
Delays |
17.64 |
18.30 |
17.40 |
18.80 |
Elements
|
Element |
1 day |
2 days |
3 days |
4 days |
|
1 |
13.80 |
12.84 |
12.25 |
12.62 |
|
2 |
23.10 |
22.00 |
24.63 |
24.25 |
|
3 |
20.30 |
18.20 |
16.43 |
15.28 |
|
4a |
4.48 |
5.77 |
5.00 |
5.11 |
|
4b |
1.72 |
1.50 |
1.66 |
2.34 |
|
5 |
6.90 |
5.77 |
6.32 |
5.51 |
|
6 |
3.79 |
3.32 |
4.14 |
4.44 |
|
7 |
2.41 |
2.67 |
3.00 |
2.50 |
|
8 |
1.04 |
1.39 |
1.48 |
1.22 |
|
9 |
6.20 |
7.50 |
6.43 |
7.70 |
|
12 |
2.41 |
3.22 |
3.02 |
2.97 |
|
13 |
11.05 |
13.36 |
13.54 |
13.34 |
|
14 |
2.76 |
2.46 |
2.10 |
2.72 |
No. of Observations
|
1 day |
2 days |
3 days |
4 days |
|
290 |
935 |
1618 |
2387 |
File Name:
parekh_1958_3429602_Page_78.png
TABLE 19a. DAILY PERCENTAGES
Dept.: C
Days:
|
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
Element Groups
|
Category |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
|
Productive |
62.5 |
69.5 |
78.1 |
66.4 |
67.8 |
69.0 |
68.7 |
|
Absent |
19.5 |
11.25 |
5.00 |
7.50 |
9.40 |
8.00 |
9.10 |
|
Delays |
18.0 |
19.25 |
16.9 |
26.1 |
22.8 |
23.0 |
22.2 |
Elements
|
Element |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
|
1 |
6.35 |
6.85 |
8.85 |
6.45 |
8.02 |
7.00 |
5.44 |
|
2 |
13.42 |
11.75 |
12.15 |
13.73 |
16.8 |
17.1 |
13.3 |
|
3 |
13.9 |
16.5 |
21.2 |
13.31 |
7.55 |
7.90 |
6.48 |
|
4a |
5.13 |
4.93 |
3.90 |
5.60 |
4.93 |
6.11 |
4.21 |
|
4b |
1.88 |
4.00 |
3.15 |
6.32 |
6.78 |
5.03 |
5.96 |
|
5 |
18.5 |
21.5 |
22.1 |
19.9 |
26.05 |
27.5 |
15.1 |
|
6 |
3.42 |
4.75 |
2.75 |
3.8 |
2.77 |
4.68 |
4.21 |
|
7w |
19.0 |
9.97 |
3.50 |
6.67 |
8.32 |
5.75 |
7.18 |
|
7p |
0.5 |
1.28 |
1.50 |
0.63 |
1.08 |
2.25 |
1.92 |
|
8 |
1.30 |
2.07 |
1.50 |
1.40 |
0.60 |
1.25 |
1.05 |
|
9 |
1.71 |
1.28 |
2.10 |
0.96 |
2.00 |
1.25 |
0.33 |
|
12 |
2.44 |
0.95 |
3.60 |
4.91 |
3.70 |
3.41 |
2.92 |
|
13 |
7.32 |
9.55 |
10.2 |
10.65 |
6.78 |
7.00 |
27.0 |
|
14 |
5.13 |
4.62 |
3.50 |
5.47 |
4.62 |
3.77 |
4.90 |
No. of Observations
|
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
|
410 |
628 |
667 |
713 |
649 |
556 |
571 |
File:
parekh_1958_3429602_Page_79.png
TABLE 19b. CUMULATIVE
PERCENTAGES
Dept. C
Days:
|
Element Groups |
1 day |
2 days |
3 days |
4 days |
5 days |
6 days |
7 days |
|
Productive |
62.5 |
66.7 |
71.2 |
69.7 |
69.4 |
69.4 |
69.2 |
|
Absent |
19.5 |
14.5 |
10.8 |
9.8 |
9.7 |
9.5 |
9.4 |
|
Delays |
18.0 |
18.8 |
18.8 |
20.5 |
20.9 |
21.1 |
21.4 |
Elements
|
Element |
1 day |
2 days |
3 days |
4 days |
5 days |
6 days |
7 days |
|
1 |
6.35 |
6.64 |
7.52 |
7.20 |
7.38 |
7.32 |
7.06 |
|
2 |
13.42 |
12.6 |
12.42 |
12.82 |
13.68 |
14.2 |
14.07 |
|
3 |
13.9 |
15.2 |
17.53 |
16.3 |
14.46 |
13.42 |
12.5 |
|
4a |
5.13 |
5.01 |
4.57 |
4.88 |
4.90 |
5.08 |
4.96 |
|
4b |
1.88 |
3.21 |
3.17 |
4.10 |
4.67 |
4.72 |
4.89 |
|
5 |
18.5 |
20.3 |
21.0 |
20.65 |
21.84 |
22.7 |
21.63 |
|
6 |
3.42 |
4.23 |
3.7 |
3.72 |
3.52 |
3.70 |
3.77 |
|
7w |
19.0 |
13.44 |
9.5 |
8.72 |
8.65 |
8.20 |
8.06 |
|
7p |
0.5 |
1.06 |
1.25 |
1.08 |
1.08 |
1.25 |
1.34 |
|
8 |
1.3 |
1.76 |
1.69 |
1.57 |
1.34 |
1.44 |
1.31 |
|
9 |
1.71 |
1.54 |
1.82 |
1.53 |
1.63 |
1.57 |
1.42 |
|
12 |
2.44 |
1.54 |
2.28 |
3.12 |
3.14 |
3.14 |
3.23 |
|
13 |
7.32 |
8.66 |
9.27 |
9.68 |
9.07 |
8.75 |
11.21 |
|
14 |
5.13 |
4.81 |
4.28 |
4.63 |
4.64 |
4.51 |
4.55 |
No. Obs.
|
1 day |
2 days |
3 days |
4 days |
5 days |
6 days |
7 days |
|
410 |
1038 |
1705 |
2428 |
3067 |
3623 |
4194 |
File Name:
parekh_1958_3429602_Page_80.png
TABLE 20a. DAILY PERCENTAGES
Dept. D
|
Day |
1st |
2nd |
3rd |
4th |
5th |
Element Groups
|
Category |
1st |
2nd |
3rd |
4th |
5th |
|
Productive |
62.2 |
59.0 |
59.75 |
61.1 |
74.3 |
|
Absent |
18.7 |
12.4 |
17.05 |
16.7 |
6.7 |
|
Delays |
19.1 |
28.6 |
23.2 |
22.2 |
19.0 |
Elements
|
Element |
1st |
2nd |
3rd |
4th |
5th |
|
1 |
7.84 |
6.82 |
12.7 |
9.2 |
13.0 |
|
2 |
13.45 |
15.45 |
16.3 |
19.2 |
21.25 |
|
3 |
14.7 |
0.0 |
4.7 |
6.61 |
12.4 |
|
4a |
9.55 |
6.36 |
9.78 |
5.00 |
9.84 |
|
4b |
1.95 |
3.13 |
1.84 |
3.16 |
0.91 |
|
5 |
9.55 |
4.09 |
6.70 |
4.84 |
8.25 |
|
6 |
2.45 |
4.09 |
2.90 |
3.39 |
2.54 |
|
7 |
18.7 |
12.4 |
17.05 |
16.7 |
6.7 |
|
8 |
4.90 |
3.13 |
2.90 |
1.22 |
0.68 |
|
9 |
2.21 |
5.91 |
2.15 |
2.58 |
3.17 |
|
12 |
2.70 |
9.39 |
3.98 |
4.51 |
1.96 |
|
13 |
9.55 |
23.6 |
11.3 |
17.4 |
15.55 |
|
14 |
2.45 |
5.63 |
4.70 |
6.14 |
3.81 |
No. of Observations
|
1st |
2nd |
3rd |
4th |
5th |
|
408 |
220 |
552 |
620 |
315 |
File:
parekh_1958_3429602_Page_81.png
TABLE 20b. CUMULATIVE
PERCENTAGES
Dept. D
Days
|
Element Groups |
1 day |
2 days |
3 days |
4 days |
5 days |
|
Productive |
62.2 |
61.1 |
60.5 |
60.7 |
62.6 |
|
Absent |
18.7 |
16.5 |
16.7 |
16.7 |
15.3 |
|
Delays |
19.1 |
22.4 |
22.8 |
22.6 |
22.1 |
Elements
|
Element |
1 day |
2 days |
3 days |
4 days |
5 days |
|
1 |
7.84 |
7.49 |
9.92 |
9.67 |
10.15 |
|
2 |
13.45 |
14.15 |
15.17 |
16.55 |
17.25 |
|
3 |
14.7 |
9.55 |
7.29 |
7.05 |
7.85 |
|
4a |
9.55 |
8.44 |
9.08 |
7.67 |
8.00 |
|
4b |
1.95 |
2.34 |
2.12 |
2.49 |
2.29 |
|
5 |
9.55 |
7.65 |
7.20 |
6.40 |
6.66 |
|
6 |
2.45 |
3.02 |
2.96 |
3.11 |
3.02 |
|
7 |
18.70 |
16.5 |
16.7 |
16.7 |
15.3 |
|
8 |
4.90 |
4.30 |
3.64 |
2.80 |
2.40 |
|
9 |
2.21 |
3.50 |
2.88 |
2.78 |
2.84 |
|
12 |
2.70 |
5.10 |
4.57 |
4.55 |
4.16 |
|
13 |
9.55 |
14.46 |
14.4 |
15.45 |
15.45 |
|
14 |
2.45 |
3.50 |
4.07 |
4.78 |
4.63 |
No. of Observations
|
1 day |
2 days |
3 days |
4 days |
5 days |
|
408 |
628 |
1180 |
1800 |
2115 |
File:
parekh_1958_3429602_Page_82(1).png
Header
CHART 4.1
FREQUENCY DISTRIBUTION
ALL DEPARTMENTS
ELEMENT & GROUP: INDIRECT WORK
Class Intervals (with
Frequency Marks)
24–25.9
26–27.9
28–29.9
30–31.9
32–33.9
34–35.9 X
36–37.9
38–39.9
40–41.9 XX
42–43.9 X
44–45.9 XXXX
46–47.9 XXXX
48–49.9 XXX
50–51.9 XXXX
52–53.9 XXXX
54–55.9 XXXX
56–57.9 XXXX
58–59.9 XXXXX
60–61.9 XXXXX
62–63.9 XXXXXXX
64–65.9 XXXXXXX
66–67.9 XXXXXXXXXX
68–69.9 XXXXXXXX
70–71.9 XXXXX
72–73.9 XXX
74–75.9 XXXXX
76–77.9 XXXXX
78–79.9 XXXX
80–81.9 XXXXXXXXXXXX
82–83.9 XXXXXXXXXX
84–85.9 XXXXXXXXXXXX
86–87.9 XXXXXXXXX
88–89.9 XXXXXXXX
90–91.9 XX
92–93.9 X
94–95.9 X
96–97.9 XX
98–99.9
Frequency Scale (Bottom Axis)
FREQUENCY: 0 2
4 6 8 10 12
14 16
File:
parekh_1958_3429602_Page_83.png
CHART 2
FREQUENCY DISTRIBUTION
ALL DEPARTMENTS
ELEMENT GROUP: "SUPPORTING DELAYS"
D (G) – Class Intervals vs
Frequency (Marked by X)
0 – 1.9 X
X X
2 – 3.9 X X
X X
4 – 5.9 X X
X X X
X
6 – 7.9 X X
X X X
8 – 9.9 X X
X X X
10 – 11.9 X X
X X X
X X X
X X
12 – 13.9 X X
X X X
X X
14 – 15.9 X X
X X X
X
16 – 17.9 X X
X X X
18 – 19.9 X X
X X X
20 – 21.9 X X
X X X
22 – 23.9 X X
X X
24 – 25.9 X X
X
26 – 27.9 X X
X X X
28 – 29.9 X X
X X X
30 – 31.9 X X
X
32 – 33.9 X X
X
34 – 35.9 X X
X
36 – 37.9 X X
38 – 39.9 X
40 – 41.9 X X
X X
42 – 43.9 X X
44 – 45.9 X X
46 – 47.9
48 – 49.9 X X
X
Frequency Scale (Bottom Axis)
FREQUENCY: 0
2 4 6
8 10
File:
parekh_1958_3429602_Page_91.png
Page Number: 88
Content:
APPENDIX
File:
parekh_1958_3429602_Page_92.png
ACTIVITY KEY
DATE:
DEPARTMENT:
REMARKS:
Activity Codes
- Writing operations
- Handle papers
- Operate office equipment
- Conversation
- Filing
- Walking
- Absent
- Use telephone
- Counter service
- Wait on customer
- Make sale
- Delay
- Miscellaneous
- Relax
Work Cycle Table Structure
|
Worker |
Cycle 1 |
Cycle 2 |
Cycle 3 |
Cycle 4 |
Cycle 5 |
Cycle 6 |
Cycle 7 |
Cycle 8 |
File:
parekh_1958_3429602_Page_93.png
Page No.: 90
CONCLUSION
In the present investigation,
the main attention was directed towards estimating the rates of different types
of non-productive activities of a group of clerical workers; a field generally
believed to be outside the domain of the time study analyst. For the first
time, the qualitative approach of sampling has made it possible to obtain
hitherto unknown detailed information about the work performance of white
collar workers.
The findings of this study
show that, as an average of the four departments, about 20 per cent of the
working time was reported as "supporting delays." The total personal
delays, including the official rest periods, constituted approximately another
15 per cent of the working time. The level of efficiency, by simple
subtraction, was 65 per cent. This may represent a satisfactory level to some
managements. The need for certain amount of non-productive activity for optimal
results may also be recognized. But the fact still remains that a program of
work simplification in the offices is as much of a necessity as the standard
methods in industrial operations. This alone, without upsetting the delicate
balance of human physiological limits, could lead to higher levels of
efficiency so essential to an economy where electronic brains are threatening
to replace human beings.
A few remarks in connection
with the design and execution of the sampling plan and its effect on the
results are in order. In the present study, a scheme of systematic sampling was
employed, but this, by no means, rules out the use of random sampling in
File:
parekh_1958_3429602_Page_94.png
Page No.: 91
similar studies. In fact, if
the study could be conducted over
a longer period, a combination of systematic and random sampling
would yield better results. The experience further dictates the
necessity of observing a bigger group of workers with a better
standardization of work methods and functions. This means an
essentially homogeneous population, a condition not obtained in
the present study. A single homogeneous population is also
necessary if an analysis of variance is to be employed to study
the variation among workers and among periods of time.
The correct determination of the cause of absence of a worker
from the department is a problem that deserves greater attention,
whenever such delays are frequent and long. In such a situation, a
better understanding of the work procedures is necessary.
The frequency distribution curves are not binomially distributed,
for reasons mentioned under "Discussion of Results." Rather than
assume a binomial distribution, it is possible to take averages of
sample groups and apply the central limit theorem which states that
the averages will tend toward a normal distribution, regardless of
the underlying distribution. One way to accomplish this would be to
break down the working day into periods of suitable lengths of time.
These periods would then represent sample groups which could be used
for control charts. A stratified sampling should be employed where
the probability of an event is suspected to vary from one period to
another.
File:
parekh_1958_3429602_Page_95.png
BIBLIOGRAPHY
Abruzzi, Adam, Work,
Workers, and Work Measurement, Columbia University Press, New York, 1956.
Arkin, Herbert and Colton
Raymond, Statistical Methods, Barnes and Noble Inc., New York, 1956.
Allderige, John M., "Work
Sampling Without Formulas," Factory Management and Maintenance,
Vol.112, No.3, pp.136–138, March, 1954.
Barnes, Ralph M., Motion
and Time Study, 4th ed., John Wiley and Sons, New York, 1958.
Barnes, Ralph M., Work
Sampling, John Wiley and Sons, New York, 1957.
Barnes, Ralph M., and Robert
B. Andrews, "Performance Sampling in Work Measurement," Journal of
Industrial Engineering, Vol.6, No.6, pp.8–18, November–December, 1955.
Bogenrief, C. A., "Work
Sampling to Measure Indirect Work for Cost Control," Factory Management
and Maintenance, Vol.110, No.12, pp.113–114, December, 1952.
Brisley, C. L., "How You
Can Put Work Sampling to Work," Factory Management and Maintenance,
Vol.110, No.7, pp.84–89, July, 1952.
Cogan, A. J., and G. N.
Stillan, "A Quick New Way to Get Downtime Data," Factory
Management and Maintenance, Vol.110, No.3, pp.136–137, March, 1952.
Conway, R. W., "Some
Statistical Concepts in Work Sampling," Journal of Industrial
Engineering, Vol.8, No.2, March–April, 1957.
Correll, D. S., and Ralph M.
Barnes, "Industrial Application of the Ratio-Delay Method," Advanced
Management, in two parts, Vol.15, No.8, pp.10–12, and Vol.15, No.9,
pp.15–18, August–September, 1950.
Cote, L. J., and B. J. Scott,
"Comparison of All-Day Time Study with Work Sampling by Use of Analysis of
Variance," Journal of Industrial Engineering, Vol.7, No.1,
pp.31–34, Jan.–Feb., 1956.
Davidson, H. O., Functions
and Bases of Time Standards, American Institute of Industrial Engineering,
Columbus, Ohio, 1952, 403 pp.
Helland, R. E., and W. J.
Richardson, Work Sampling, McGraw Hill Book Company, Inc., New York,
1957.
File:
parekh_1958_3429602_Page_96(1).png
📚 References
MacNiece, E. H.,
"How Work Sampling Can Help You Rate Your Key People,"
Factory Management and Maintenance, Vol.110, No.10, pp.98–100, October,
1952.
MacNiece, E. H.,
"Work Sampling: Newest Way to Check Maintenance Efficiency,"
Factory Management and Maintenance, Vol.111, No.7, pp.110–112, July,
1953.
Malcolm, D. G., and L. L.
Sammet,
"Work Sampling Applications,"
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Sammet,
"Work Sampling Studies,"
Journal of Industrial Engineering, Vol.5, No.4, July, 1954.
McAllister, G. E.,
"Random Ratio-Delay,"
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Morrow, R. L.,
Motion Economy and Work Measurement,
Ronald Press Co., New York, pp.297–319, 1957.
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Motion and Time Study,
Richard D. Irwin, Homewood, Illinois, 1955, pp.334–342.
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"Using Ratio-Delay Studies to Set Allowances,"
Factory Management and Maintenance, Vol.106, No.10, pp.92–94, October,
1948.
Rowe, A. J.,
"The Work Sampling Technique,"
Transactions of the ASME, Vol.76, No.2, pp.331–334, February, 1954.
Schaeffer, F. H.,
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🎥 MOTION PICTURES
"The Ratio-Delay Study—A
New Tool of Work Simplification,"
Wolverine Tube Division, Calumet and Hecla Inc., Detroit 9, Michigan.
"Work Sampling
Demonstration,"
Wolverine Tube Division, Calumet and Hecla Inc., Detroit 9, Michigan.
"Introduction to Work
Sampling,"
Department of Visual Instructions, University Extension,
University of California, Los Angeles, 24, California.
- Cleaned minor OCR inconsistencies (spacing,
punctuation).
- Preserved original formatting (titles, italics
represented with quotes).
- Grouped logically under References and Motion
Pictures.
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