This document discusses work study techniques used to improve productivity and efficiency. It defines work study and describes its objectives of analyzing current work methods, establishing standard times, and improving efficiency. It outlines various work study techniques including method study, work measurement, time study procedures and tools. Principles of motion economy are discussed to reduce ineffective movements and optimize workplace layout, tool design and human motions. The document provides examples and diagrams to illustrate techniques like process charts, therbligs, micro-motion study, work measurement and time study.
1. DHAANISH AHMED COLLEGE OF ENGINEERING
DEPARTMENT OF MECHANICAL ENGINEERING
PRODUCTION PLANNING AND
CONTROL-WORK STUDY
SUBMITTED BY GUIDED BY
V.ATTIMURUGAN(B.E) Dr. R.SENTHILKUMAR.M.E, Ph.D.,
HEAD OF DEPARTMENT
2.
3. Work Study
Definition of Work Study
According to the British Standard Institution,
“Work Study is a generic term for those
techniques, particularly Method Study and Work
Measurement, which are used in all its context,
and which lead systematically to the investigation
of all the factors, which affect the efficiency and
economy of the situation being reviewd in order
to effect improvement”.
4. Objectives of Work Study
Objectives of Work Study
To analyze the present method of doing the job in
order to develop a better method.
To measure the work content of the job by
measuring the time required to do the job for a
qualified worker and hence to establish the
standard time.
To increase the productivity by ensuring best
possible use of human, machine and material
resources and to achieve best quality
product/service at minimum possible cost.
To improve operational efficiency.
5. Scope of work study
• Method study and work measurement are
closely linked to each other as both are
associated with work study.
• Method study reduces the content of job and
work measurement investigates and reduces
ineffective time associated with job with
establishment of standard time.
• This results into efficient working operations
leading to increase in productivity of that
process
6. Benefits of Work Study
Increased productivity and operational efficiency
Reduced manufacturing cost.
Improved work place layout.
Better manpower planning and capacity planning
Fair wages to employees.
Better working conditions to employees
Improved work flow.
Reduced material handling cost.
Provides a Standard of Performance to measure
labour efficiency.
Better Industrial Relations and Employee morale.
Basis for sound incentive schemes.
Provides better job satisfaction to employees
9. Method Study - Introduction
Method study can be defined as “Systematic
recording and critical examination of existing
and proposed ways of doing work, as a means of
developing and applying easier and more
effective method and thereby reducing costs”.
Used to analyze
• Movement of body, people, or material
• Activities of people & machines
10. Method Study Objectives
Improvement of processes and procedures so as to
improve productivity and thereby reduce operating
cost.
Improvement in the design of plant and equipment.
Improvement of layout.
Improvement in the use of men, materials and
machines.
Economy in human effort and reduction of
unnecessary fatigue.
To Standardise work methods or processes,
machinery, equipments and tools.
Development of better working environment.
11. Method Study - Benefits
1. Work Simplification
2. Improved working method
3. Better product quality
4. Improved workplace layout
5. Improved equipment Design.
6. Better working conditions/environment
7. Better materials handling and lesser material handling cost.
8. Improved work flow
9. Less fatigue to workmen.
10. Optimum utilization of all resources.
11. Shorter production cycle time.
12. Higher job satisfaction for workmen.
13. Reduced material consumption and wastages.
14. Reduced manufacturing cost and higher productivity.
13. Procedure to accomplish method study, called"SREDIM"
shall be as follow:
1. Select: the job or operation that needs improvement,
2. Record: all facts, how work is done by chart methods,
3. Examine: every aspect of the job by asking; what, why,
where, when, who and how
4. Develop: review ideas, eliminate, simplify, combine,
rearrange, make new method which more safe, chart new
method, submit for approval,
5. Install: the new method, consider best time to
introduce, convince all, train users,
6. Maintain: check frequently, match results, correct
deviations
15. CHARTS
1. Outline process chart.
2. Flow process chart (man-type, material-type and
equipment-type): This is the use of symbols and
description to chart the sequence of work. The process,
then, show what is happening at different stages.
The distances and time may be given.
3. Two hands process charts.
4. Multiple activity charts: This technique is used to solve
problems where a number of items are dependent on each
other. The aim is to reduce idle times by using the
optimum number of each item. It depicts the occupied
times-broken down into the number of different activities
and the idle times both for the original and proposed
methods of doing the job.
16. Diagrams and models (2-D and/or 3-D)
1. Flow diagrams, which is the use of symbols for
flow process charts, superimposed on drawings
and the "descriptions" are not necessary.
2. String diagrams, which is used for solving
movement problems since it shows congestions
and excessive distances.
3. Cut-out templates (2-D models).
4. 3-D models.
Photography
1. Photographs,
2. Films,
3. Video.
19. Outline Process Chart
Definition:
An outline process chart is a process chart
giving an overall picture by recording in
sequence only the main operations and
inspections.
While preparing the outline process chart we
use Symbols of Operation and Inspection
A brief note of the nature of each operation is
made beside the symbol
In an outline process chart, only the principal
operations and the inspections carried out are
recorded to ensure effectiveness.
21. FLOW PROCESS CHART
Definition:
Flow process charts are graphic
representations of thesequences of operations,
transportation, inspections, delays and
storages occurring during a process or a
procedure and include information considered
for analysis such as, time required and distance
moved.
22. Types of Flow Process Charts
Material or product type.
Man type.
Machine type or equipment.
Material or product type flow process chart:-
Records what happens to the material or product i.e. the changes the
material or product undergoes in location or condition (includes
operation and transportation).
Man type process flow process chart:-
Records the activities of worker or operator i.e. what a worker or
operator does. In this type of chart usually storage term is not
applicable.
Machine or equipment type flow process charts:- Records
the manner in which a machine or an equipment is used.
26. Two Hand Process Chart
Two-Handed Flow Process Chart, is a motion study
where the study is done to analyse the motions used by
the worker in performing an activity. In this chart the
activities of worker’s hands (or limbs) are recorded in
their relationship to one another.
Two Hand Process Chart
28. MULTPLE ACTIVITY CHART
Definition:
A Multiple activity chart is a form of process chart recording
the related sequence of work of a number of operators and/or
machines on common time scale. In it, the activities of more
than one item, worker, machine or equipment are recorded on a
common time scale to show their inter relation ship.
Also known as Gang Process Charts
TYPES:
Man - Machine chart: One man handling one job or one
machine.
Man - Multi machine chart: One man handling a numbers of
machines.
Machine Multi - man chart: A group or gang doing collectively
one job as in riveting.
Multi – Man - Machine chart: A number of persons working on
a computer system.
30. Recording Techniques - Diagrams
Indicates the path of movement
Study of traffic & frequency over different
routes of plant
Identification of back-tracking & obstacles
during movements
Study of different layout plans & select
optimal layout
31. Flow Diagram
1)Layout of w/p is drawn to scale
2)Relative positions of m/c tools, work benches, etc
are marked
3)Path followed by the subject under study is traced
by drawing lines
4)Each movement is serially numbered and
indicated by arrow for direction
5)Different colors are used to denote different types
of movements
33. String Diagram
String/Thread is used to measure the
distance
Records the pattern of movement of a worker
working within a limited area during a
certain period of time
Repetitive movements can be conveniently
traced
34. PROCEDURE:
1)Layout of the w/p or factory is drawn to scale
on a soft board
2)Pins are fixed into boards to mark the location
of work stations,
3)Pins are also driven at the turning point of the
routes
4)A measured length of thread is taken to trace
the movement (path)
5)The distance covered by the object is obtained
by measuring the remaining part of the thread
and subtracting it from the original length
35.
36. MICRO-MOTION STUDY
Micro motion study is the study of fundamental element or
subdivision of an operation by means of a motion picture
camera and a timing device which accurately indicates the time
Therbligs
On analysing the result of several motion studies conducted,
Gilbreths concluded that any work can be done by using a
combination of some or all of 17 basic motions, called
Therbligs (Gilbreth spelled backward). These can be classified
as effective therbligs and ineffective therbligs. Effective
therbligs take the work progress towards completion.
Attempts can be made to shorten them but they cannot be
eliminated. Ineffective therbligs do not advance the progress
of work and therefore attempts should be made to eliminate
them by applying the Principles of Motion Economy. Table
gives different therbligs along with their symbols and
descriptions interval on motion picture film.
38. Objective of Micro motion study
1.To find most efficient way of doing work
2. Helps to study repetitive short cycle operation which
cannot be studied by ordinary method.
3.To train operator regarding motion economy.
4. It is permanent means of keeping record of method.
5. It assists in research project in the field of work study
6. It helps to study complex activities of short duration
performed with extreme rapidity.
39. Procedure/ Step in micro motion study
1. Filming the operation to be studied.
2. Analyzing the film.
3. Charting the result of analysis.
4. Developing and improve method.
Filming :-
The filming speed is 16 frames per second with a 16 mm movie
camera.
Main advantages of films over visual methods are:
Permit greater detailing than eye observation;
Povide greater accuracy than pencil, paper and stop watch;
More convenient;
Provide a positive record;
Help in the development of the work study person
40. Film Analysis:-
1.A Projector is used for analysis purpose.
2. Projector runs the films very slowly and film can be stopped &
reversed whenever required.
41. Cyclegraph
A record of path of movements, usually traced by
a continuous source of a light on a photograph.
The path of movement of a hand, may be
recorded on a photograph by putting a ring
carrying small light on worker’s hand.
A path of light resembling a white wire is seen.
Later it is used with a stereoscopic camera to
show the path in three dimensions .
43. Chronocyclograph
This is a development of the cycle graph by
interrupting the flow of current so as to obtain, in the
resulting sequence of flashes, a record of the time and
direction of the motions under observation. The
resulting image was a chronocyclograph.
The path of light appears as a series of pear-shaped
dots, the movement being in the direction in which
the dots point.
The spacing between the dots indicate the speed of
movement and show acceleration and deceleration.
This is done by using a turning fork, which is
vibrating at a known speed, and connected with a
“make and break” contact.
45. MICROMOTION STUDY – SIMO Chart
• “SIMO” stands for simultaneous-Motion Cycle chart. It is
one of micro motion study devised by Gilbreth.
• It presents graphically the separable steps of each pertinent
limb of the operator under study.
• It is an extremely detailed left and right hand operation
chart.
• It records simultaneously the different therbligs performed
by different parts of the body of one more operators on a
common time scale.
• The movements are recorded against time measured in
“Winks” (1 wink= 1/2000 minute).
• These are recorded by a “Wink Counter” positioned in such
a location that it can be seen rotating during filming
process.
47. MEMO-MOTION STUDY
In memomotion study, the camera speed is at
60 or 100 frames per minute
It is a form of time lapsed cine-photography
Time interval lies b/w 1/2sec to 4sec
10 or 20 min. may be compressed into 1min
48. PRINCIPLES OF MOTION ECONOMY
These principles can be considered under three
different groups;
Those related to the use of the human body
Those related to the workplace arrangement
Those related to the design of tools &
equipment
49. Principles related to the use of human
body
Both hands should begin and end their basic
divisions of activity simultaneously & should not be
idle at the same instant, except during the rest
periods.
Momentum should be employed to assist the
worker wherever possible, and it should be reduced to
a minimum if it must be overcome by muscular effort.
Continuous curved motions should be preferred to
straight line motions involving sudden and sharp
changes in the direction.
Work that can be done by the feet should be
arranged so that it is done together with work being
done by the hands.
Twisting motions should be performed with the
elbows bent.
50. Principles related to the arrangement &
conditions of workplace
Fixed locations should be provided for all tools
and materials so as to permit the best sequence
and eliminate search and select.
Gravity bins and drop delivery should be used to
reduce reach and move times.
Use may be made of ejectors for removing
finished parts.
Work table height should permit work by the
operator in alternately sitting and standing
posture.
Glare-free adequate illumination, proper
ventilation and proper temperature should be
provided.
51. Principles related to the design of tools and
equipment
Use colour, shape or size coding to maximize speed
and minimize error in finding controls.
Use simple on/off, either/or indicators whenever
possible.
All levers, handles, wheels and other control devices
should be readily accessible to the operator and
should be designed so as to give the best possible
mechanical advantage.
Use quick acting fixture to hold the part/material
upon which the work is being performed.
Use stop guides to reduce the control necessary in
positioning motions.
Operating, set-up and emergency controls should be
grouped according to the function.
52.
53. WORK MEASUREMENT / TIME STUDY
Work measurement refers to the estimation of
standard time for an activity, that is the time
allowed for completing one piece of job by
using the prescribed method. Standard time
can be defined as the time taken by an average
experienced worker for the job with provisions
for delays beyond the worker's control.
54. WORK MEASUREMENT OBJECTIVES
Comparing alternative methods
Assessing the correct initial manning
Realistic costing
Delivery date of goods
Cost reduction & cost control
Training new employees
Find ineffective time in a process
Evaluate worker's performance
Facilitate operations scheduling
Establish wage incentive schemes
55. WORK MEASUREMENT TECHNIQUES
Time study (stop watch technique)
Work sampling
Synthetic data
Analytical estimating
Predetermined Motion Time Study (PMTS)
57. TIME STUDY – BASIC STEPS
a. Obtaining and recording all available information
about the job, operator and the surrounding conditions
likely to affect the execution of the work
b. Recording the complete description of the method,
breaking down the operation into 'elements'
c. Measuring with a stopwatch and recording the
time taken by the operator to perform each element of
the operation
d. Assessing the rating
e. Extending observed time to 'basic times'
f. Determining the allowances to be made over and
above the basic time for the operation
g. Determining the 'standard time' for the operation
58. TIME STUDY EQUIPMENT
1. Fly back Method:
Here the stop watch is started at the beginning of the first element. At
the end of the element the reading is noted in the study sheet. At the
same time, the stop watch hand is snapped back to zero. This is done
by pressing down the knob, immediately the knob is released. The
hand starts moving from zero for timing the next element. Thus the
timing for each element found is called observed time.
2. Continuous method:
Here the stop watch is started at the beginning of the first element.
The watch runs Continuously throughout the study. At the end of each
element the watch readings are recorded on the study sheet. The time
for each element is calculated by successive subtraction. The final
reading of the stop watch gives the total time known as observed
time.
59. Equipments used to measure time using Stop
watch:
Digital or electronics stop watch
Electronic data collector and computer
Observation board
Observation sheet
Stationary – Pen, Pencil, Eraser, Calculator
60. TYPES OF ELEMENTS
A repetitive element
An occasional element
A constant element
A variable element
A manual element
A machine element
Governing element
A foreign element
61. PERFORMANCE RATING
Process of adjusting the actual pace of
working of an operator by comparing it with
mental picture of pace of an operator working
at normal speed
Performance rating methods
Speed rating
Westing house method of rating (S,E,C,C)
Synthetic rating (R = P/A)
Objective rating
64. WORK MEASUREMENT TECHNIQUES
1.Work sampling Procedure
A technique of getting facts about utilization of machines
or human beings through a large number of
instantaneous observations taken at random time
intervals.
Estimates percent of time a worker spends on various
tasks
Determines how employees allocate their time
Used to set staffing levels, reassign duties, estimate costs,
and set delay allowances
65. Work sampling Procedure
Step 1 . Define the problem.
Step 2. Design the sampling plan.
Step 3. Contact the persons
Step 4. Make the observations
Step 5. Obtain and record other information.
ep 6. Calculate the standard time per piece.
66. 2.Predetermined Motion Time Study (PMTS)
A procedure that analyzes any manual
activity in terms of basic or fundamental
motions required to perform it.
Each of these motions is assigned a
previously established standard time value
and then the timings for the individual motions
are synthesized to obtain the total time needed
for performing the activity.
The main use of PMTS lies in the
estimation of time for the performance of a
task before it is performed.
67. Some commonly used PMT systems are:
Method Time Analysis
Work Factor
Basic Motion Time
Method Time Measurement