PMTS mechanical engineering

1. is the application of technique designed to establish
the time for a qualified worker to carry out a specified
job at a defined level of performance.

2.  Designed to establish the time for a qualified worker
to carry out a specified job.
 Provides the management with a means of
measuring the time taken in the performance of an
operation.
 Used to set standard times for carrying out the work
and standard output level.

3. 1. To reveal the existence of ineffective time.
2. To compare the efficiency of alternative methods.
3. To balance the work of members of a team.
4. To determine the number of machines an operator
can run.
5. To set the time standards to carrying out the work.
6. To provide information to estimate tenders, selling
prices and delivery promises.
7. Helps to plan and schedule the production.
8. Helps to carry out the effective utilization of available
capacity.

4. 9. Used as a basis for realistic and fair incentive scheme.
10. To compare the actual time and target time.
11. To control the labour cost.
12. To enable standard costs to be fixed and maintained.
13. Used as a basis for labour budgeting and budgetary
control system.

6. 1. Select- the work to be studied.
2. Record- all the relevant data.
3. Examine- all the recorded data.
4. Measure- the time required to complete each
element.
5. Compile- the standard time for the operation.
6. Define- the series of activities and method of
operation.

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

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

9.  An element is an distinct part of a specified job
selected for convenience of observation,
measurement and analysis.
 A work cycle is the sequence of elements which are
required to perform a job or yield a unit of
production. The sequence may sometimes include
occasional elements.
 For each job, a detailed breakdown of the complete
job into elements is necessary.

10.  To ensure that productive work (or effective time) is
separated from unproductive activity (or ineffective
time).
 To ensure better and accurate rating.
 To identify and distinguish different types of
elements
 To isolate elements involving high degree of fatigue
to allocate fatigue allowances more accurately
 To facilitate checking of method.

11.  To enable a detailed work specification to be
prepared.
 For compilation of standard data for the recurring
elements.
 To facilitate assessment of performance rate in a
better way for each individual element.

12. i. Each element should be as short in duration as
possible.
ii. Each element can be timed accurately and reliably.
iii. Manual elements should be separated from machine
elements.
iv. Constant elements should be separated from
variable elements.
v. Certain elements which do not occur in each work
cycle should be separated and timed separately.
vi. Handling time should be separated from machining
time.

13.  New Job: The job in question is a new one, not previously
carried out (new product, component, operation or set of
activities)
 Change in method/material: A change in material or
method of working has been made and a new time
standard is required.
 Complaint from worker: A complaint has been received
from a worker or worker’s representative about the time
standard for an operation.
 Bottleneck in operations: A particular operation appears
to be a “bottleneck” holding up subsequent operations
and possibly previous operations.
 New incentive scheme: Standard times are required
before an incentive scheme is introduced.

14.  Low output: To carry out investigation when output
of plant is low.
 Alternative Methods: For comparing alternative
methods and find out the best one.
 Excessive cost: When the cost of particular job
appears to be excessive.

15. A work cycle is the sequence of elements which are
required to perform a job.
It starts at the beginning of the first element of the
operation and continues to the same point in a
repetition of operation.
The time required to complete each element vary
slightly from cycle to cycle.
This variation in time introduces a sampling error.
Commonly in industries 95% confidence level is used
and the accuracy desired is ±5%

16. If n=required no. of observations to predict the true
time within ±5% accuracy and 95% confidence level,
then statistically,
n=[(40√n’∑x2-(∑x)2)/ ∑x]2
where,
n’= number of preliminary readings
n= sample size(no. of observations required)
∑x= the sum of preliminary set of individual
observations
∑x2= sum of the square of individual observations of the
preliminary set of readings.

17.  Work measurement technique for recording the times
and rates of working for the elements of a specified job
under specified condition; for analyzing the data so as to
obtain the time necessary for an operator to carry out
the job at a defined level of performance.
The equipments required fro time study consists of:
1) Stop Watch
a. Flyback decimal minute stop watch
b. Non-flyback stop watch
2) Time Study Board
3) Time Study Forms

18. 4) A small calculator
5) A reliable clock, with a seconds hand
6) Measuring instruments such as a tape measure,
steel rule, micrometer, spring balance etc.

19.  There are two methods used for timing with stop
watch.
1) Cumulative timing:
o In this method, the watch is started from the zero
position at the beginning of the study and not
stopped through out the study.
o The analyst simply records the stopwatch reading
at the end of each element.
o The elemental times are obtained at the end of the
study by taking the difference between successive
readings.

20. 2) Flyback/Snap back timing:
o The analyst simultaneously notes the stopwatch
reading at the end of each element .
o Then brings the hands to zero position by pressing
the winding knob.
o Since the hands are snapped back to zero at the
beginning of each element, the recording readings
represent elemental times.

22. Steps:

24. 1) Observed or Actual Time:
o It is the actual time taken in completing the job.
o If an operator work with 100% efficiency then
observed time will be equal to normal/basic time.
o it can be used in:
i. Method Study
ii. Plant Layout
iii. Realistic setting of starting and finishing times of
operations.

25. 2) Normal time:
o It is the productive time required to perform a job
utilizing appropriate work method and work place
layout at normal pace.
o It is associated with a set of tasks and is determined
by the actual measurement and pace adjustment.
o Avg. Observed/Actual time X Performance Rating
100

26. 3) Standard Time:
o It is the time required by an operator of average skill,
who uses an average amount of effort.
o When operator is working under existing working
condition using the specific method and machines
at a standard pace.
o Standard Time= Normal time + Allowances

27.  Rating means gauging and comparing the
performance or pace rate of a worker against a
standard performance.
 It can be calculated as:
Observed performance X 100
Normal Performance
 The time standard formed must be with in the
working capacity of majority of workers in the unit.

28.  It is used to set the normal time for a normal worker.
 Actual time or observed time is multiplied with this
factor to obtain the normal time.
 Expressed as a percentage of the efficiency of
representative worker .
 It shows how efficient an operator is in comparison
to his fellow operators.
 Also known as ‘levelling factor’.

29. Various rating techniques are as follows:
1) Speed rating
2) Westing-house system of rating
3) Synthetic rating
4) Objective rating
5) Psychological Evaluation of Performance rating

30.  It consists of judging the speed of the operator’s
movements in relation to a normal pace.
 It can be applied to different elements of job.
 Mathematically,
Normal time= Observed time X Worker’s speed
Speed Expected

31.  A four factor system developed at Westing house by
C.E. Bedaux.
 Four factors are:
i. Skill
ii. Effort
iii. Conditions
iv. Consistency
 The numerical values for each of these factors are
available in tabular form.
 The operator is watched while working and given a
value from these tables.

34.  This system was proposed by Morrow.
 This method of rating has two main advantages over
other methods. These are:
i. it does not rely on the judgment of time study
person and
ii. it gives consistent results.
 The time study is made as usual.
 Some manually controlled elements of the work
cycle are selected.
 Using a PMT system (Pre-determined motion time
system), the times for these selected elements are
determined.

35.  The times of these elements as determined are
compared with the actual observed times and the
performance factor is estimated for each of the
selected elements.
 Performance or Rating Factor, R = P / A
Where,
P = Predetermined motion time of the element, and
A = Average actual observed time of the element.
 The overall rating factor is the mean of rating factors
determined for the selected elements. This is applied
uniformly to all the manually controlled elements of
the work cycle.

37.  This was developed by M.E. Mundel.
 Tempo of doing a job, job difficulty are taken into
account.
 First of all pace rating is done and then allowance is
added to it to take care of job difficulty.
 The following six factors constitute job difficulty:
i. Amount of body used
ii. Foot pedals
iii. Bimanualness
iv. Handling requirements
v. Weight
vi. Eye-hand coordination

39.  When an operator has worked for a specified period,
he is allowed to sit on a chair and relax.
 Side by side heart rate is measured and compared
with earlier record till the rate become stabilize.
 This comparison for different jobs and workers
would help the time study observer to find out
performance rating.

40.  The normal time for an operation does not contain
any allowances for the worker.
 It is impossible to work throughout the day even
though the most practicable, effective method has
been developed.
 Even under the best working method situation, the
job will still demand the expenditure of human effort
and some allowance must therefore be made for
recovery from fatigue and for relaxation.
 Allowances must also be made to enable the worker
to attend to his personal needs.

41.  The allowances depend upon:
i. Factors related to individual worker.
ii. Factors related to the nature of the work itself.
iii. Factors related to environment
 Thus allowance is the additional time allowed to
perform the work over and above the basic time.

42. 1. Relaxation allowances:
a) Personal need allowances
b) Fatigue allowances
i. Basic fatigue allowances ii.Variable fatigue allowances
2. Contingency allowances
3. Special allowances
4. Interference allowances
5. Process allowances

43.  Relaxation allowance is an addition to the basic time
intended to provide the worker with the opportunity to
recover from the physiological and psychological effects
of carrying out specified work under specified conditions
and to allow attention to personal needs.
 The amount of allowance will depend on the nature of
the job.
 There are 2 type of relaxation allowance:
a) Personal needs allowances: This allowance provides
for the necessity to leave the workplace to attend to
personal needs such as washing, going to the lavatory or
fetching a drink . Common figures are from 5 to 7 percent
of basic time.

44. b) Fatigue allowances: It provides a worker an
opportunity to recover from physiological and
psychological effects of fatigue caused by carrying
out a specific task under specified conditions.
i. Basic Fatigue allowances: it is provided to the
worker who performs a job seated, who is engaged
on light work in good working conditions, and who
is called upon to make normal use of members of
the body. Usually, it taken as 4% of the basic time.
The personal need allowances and the basic fatigue
allowances are called as fixed allowances.

45. ii. Variable fatigue allowances: it is provided to an
operator who is engaged on medium and heavy
work, who work in a posture other than sitting.
Some of the factors to be taken into account are:
 Abnormal position
 Accident hazard of the job
 Weight lifting or use of force
 Illumination of the work site.
 Ventilation
 Temperature
 Noise
 Strain

46. A contingency allowance is a small allowance of time
which may be included in a standard time to meet
legitimate and expected items of work or delays, the
precise measurement of which is uneconomical
because of their infrequent or irregular occurrence like:
Tool breakage.
Obtaining necessary gauges, special tools from stores.
Filling coolant.
Consultation with foreman.

47. It is an allowance of time included into the work
content of the job to compensate the operator for the
unavoidable loss of production due to simultaneous
stoppage of two or more machines being operated by
him.
This allowance is applicable for machine or process
controlled jobs.
Interference allowance varies in proportion to number
of machines assigned to the operator.
The interference of the machine increases the work
content.

48.  it is provided for the activities which are not normally
a part of operation cycle, but essential for satisfactory
performance of the work.
It may be permanent or temporary.
These includes:
Start up allowance
A shut down allowance
A cleaning allowance
Tool allowance
Change over allowance
Implementation allowance

49. Policy allowances are not the genuine part of the time
study and should be used with utmost care and only in
clearly defined circumstances.
The usual reason for making the policy allowance is to
line up standard times with requirements of wage
agreement between employers and trade unions.
The policy allowance is an increment, other than
bonus increment, applied to a standard time (or to some
constituent part of it, e.g., work content) to provide a
satisfactory level of earnings for a specified level of
performance under exceptional circumstances. Policy
allowances are sometimes made as imperfect
functioning of a division or part of a plant.

50.  It is a work measurement technique in which a large
number of instantaneous observations are made at
random intervals over a specified period of time of a
group of workers, machines and processes.
 is defined as a method of finding the percentage
occurrence of a certain activity by statistical
sampling and random observations.

53.  A technique for estimating the proportion of time
that a worker or machine spends on various activities
and the idle time.
 Work sampling is a commonly used industrial
engineering technique designed to measure how
resources such as people, machines, facilities, or
equipment are used.
 The work sampling objective is to assess selected
aspects of an organization's operations. To find the
frequency of occurrence of every work element.

54.  Work sampling determines the percentage of
occurrence of certain activity by statistical sampling
and random observation.
 Work Sampling, (also referred to as random
sampling or activity sampling) is a work
measurement technique where observations about
work are collected at discrete time intervals, either
periodic or random.
 Work sampling is broadly defined as the application
of statistical sampling techniques to the study of
work activities.

55. The work sampling procedure can be divided into the
following three phases:
a) Preparation for work sampling:
i. Decide the main objective of the study.
ii. obtain the approval of the supervisor of the
department in which work sampling is to be
performed.
iii. Based upon the objectives, establish the quantitative
measure of activity.
iv. Selection and training of personnel.
v. Making a detailed plan for taking observations.

56. b) Performing work sampling:
i. Classify the different categories of activities to be
studied.
ii. Design the observation forms.
iii. Determine the number of days or shifts required for
study.
iv. Develop properly randomised times of observations.
Before actual observations are taken, the following steps are
important from the initial planning:
 Define and decide the areas to be studied and the time
limits.
 Decide the number of observations per day or per
period.

57. Decide number of locations to be observed.
Distance between two operators.
v. Observing activity and recording data.
vi. Summarising the data.
c) Evaluating and presenting of work sampling:
i. Evaluating the validity and reliability of the data.
ii. Presenting and analysing data.
iii. Planning for future studies.
 Control charts are used to evaluate the reliability of data.

58. The formula for determining the number of
observations required is given by:
P.S. = k σ = k [√P(1-P)/n]
Where,
K= a factor, value of which depends on the desired
confidence level.
P= percentage occurrence of the activity.
S= error in fraction.
n= no. of observations required for the desired
confidence level and margin of error.

62.  For ratio delay studies.
 To indicate the nature of the distribution of work
activities within a gang operation.
 To estimate the percentage of utilization of groups of
similar machines or equipment.
 To determine the productive and non- productive
utilization of clerical operations.
 To measure performance.
 To aid in job evaluation.
 To indicate how materials handling equipments are being
used.
 For appraisal of organisational efficiency.

63.  It is a less expensive procedure.
 Observers with minimal specialized training can
conduct the sampling.
 It is an effective means of collecting facts that would
not normally be collected by other means.
 Several operators or machines may be observed
simultaneously by a single observer.
 No mechanical device needed.
 It measures the utilization of people and equipment
directly.
 A work sampling study may be interrupted at any
time without affecting the results.

64.  It is not economical for studying a single operator or
machine, or for studying operators or machines
located over wide areas.
 It cannot provide a much detailed information .
 The operator may change his or her work pattern
upon sight of the observer.
 It is of little value in helping to improve work
methods.
 A lot of groundwork is required.
 A work sampling study made of a group obviously
presents average results, and there is no information
as to the magnitude of the individual differences.

66.  Work measurement technique whereby times
established for basic human motions (classified
according to nature of motion and the conditions
under which it is made) used to build up the time for
a job at a defined level of performance.
 Also known as Micro data which is based upon much
smaller division of motions i.e., therbligs.

67.  Very useful in Method Analysis.
 Helps modifying and improving work methods
before starting the work on the job.
 Sets time standards for different jobs.
 Assists in constructing time formulae.
 Aids in the prebalancing of the manufacturing lines.
 Provides a basis for wage plans and labour cost
estimation.
 Facilitates training of the workers and supervisor.

68.  Eliminates inaccuracies associated with stop watch
time study.
 Much effective then stop watch time study in case
of short cycle highly repetitive operations.
 Time standard for a job can be arrived at without
going to the place of work.
 No rating factor is employed like in stop watch
study.
 More reliable and accurate as compared to stop
watch time study data.
 Less time and cost associated.
 Helps in tool and product design.

69. 1. Method Time Measurement (M.T.M.)
2. Work Factor (W.F.)
3. Dimensional Motion Times (D.M.T.)
4. Basic Motion Time (B.M.T.)
5. Motion Time Analysis (M.T.A.)

70.  is a procedure which analyses any manual operation
into the basic motions required to perform it and
assigns to each motion a predetermined time value
by the nature of motion.
 Developed from motion picture studies on
industrial operations. (1 time unit= 0.0006 minute)
 Tool of method analysis that provides the answer in
terms of time.
 No use of stop watch.

71.  Developing effective methods and planning in advance
of beginning production.
 Improving existing methods.
 Establish time standards.
 Cost estimating.
 Training supervisors to become method conscious.
 Operator training.
 Determining incentives, wages rates etc.
 Research in operating methods, training and
performance rating.
 Helps in product design.
 Assist in selecting effective equipments.

72.  Movement of body can be broken up into number of
fundamental motions as follows:
 Basic manual movements (8)
 Pedal and trunk movements (9)
 Ocular movements (2)
 Data of these motions is considered in the
establishment of any motion pattern.
 Predetermined time values are given to each motion.
 All such times are added up to obtain the normal
time for the job.
 Standard time is calculated by adding suitable
allowances.

73.  Eight basic manual movements are:
1. Reach-R
2. Move-M
3. Apply Pressure-AP
4. Turn-T
5. Grasp-G
6. Position-P
7. Release-RL
8. Disengage-D

74.  Nine pedal and trunk movements are:
1. Side step
2. Turn body
3. Walk
4. Bend
5. Stoop
6. Kneel on one leg
7. Kneel on both legs
8. Foot motions
9. Sit
 Two eye movements.

75.  Movement of hands to a destination with predefined
objective.
 Time for reach depends upon:
i. The distance moved.
ii. Nature of destination.
iii. Type of reach.

76.  Classes of Reach depending on the surrounding of
object:
A. Motion of habit and is the fastest case of reach.
B. Motion to a known location of object.
C. Motion to an object jumbled with other objects,
involves search and select.
D. Reach to a single object and accurate grasp is
required. Required both sight and concentration.
E. Motion is performed to get hand into position for
the body balance for the next motion or out of way.

82.  Combination of predetermined manual motion times
and mental process time.
 Arranged to obtain an appropriate time for every manual
motion.
 Based upon performance of skilled and experienced
worker.
 1 time unit= 0.0001 minute

83.  Very simple and easy procedure.
 Quick work measurement.
 More accurate than M.T.M.
 Eliminates the use of stop watch.
 Avoids inconsistencies arising from judgement of
effort rating.
 Very precise preparation of job descriptions.
 Mental process time is taken into consideration.
 Gives a smaller time as compared to M.T.M.

84. 1. Detailed Work Factor.
2. Simplified Work Factor.
3. Abbreviated Work Factor.
4. Ready Work Factor.

85.  Includes some basic motions whose time in turn is
modified by the elements of difficulty.
 Time increases with increase in number of
difficulties.
 Number of work factors is proportional to time taken
for a motion.
 Considers the following elements of work:
a. Assemble- Putting objects together.
b. Disassemble- Separating different parts of a body.
c. Grasp- Taking hold of something.
d. Mental Process- Involves sort, inspect, recollect etc.

86. e. Preposition- Locating an article in predetermined
position.
f. Release- Releasing or letting go an object.
g. Transport- Moving an article or hand from one
place to another.
h. Use- Manipulating or causing a tool to do its work.
 Four major variables:
i. Body member which performs the motion:
a. Arm-A b. Leg-L c. Trunk-T
d. Finger-Hand (F-H) e. Foot- Ft
f. Forearm Swivel- FS

87. ii. Distance
iii. Weight or Resistance
iv. Manual Control
a. Steering or Directional Control (S)
b. Change of Direction Work Factor (U).
c. Precaution or Care (P).
d. Manner of Terminating the Motion(D-Definite stop).
 Steps involved in finding the operation time:
a. Analyse the job in detail into individual motions.
b. Determine the number of work factors associated
with each motion.

88. c. Find the time for each motion from the table
provided.
d. Add the times for each motion.
e. Add the appropriate allowances to arrive at standard
time.