2. Arvind Shrouti,Option Positive
What is work study?
Work study is:
The systematic examinations of the methods
of carrying on activity
tools to in improving productivity is work study.
To improve effective use of resources
To set up standards of performance
Simplifying or modifying the methods of operation
Reduces unnecessary or excess work
Contributes to industrial safety by identifying hazardous work and
developing safer methods
3. Work study
Method study
Work
measurement
A generic term for those techniques, particularly method study and work
measurement, which are used in the examination of human work in all its
contexts, and which lead systematically to the investigation of all the
factors which affect the efficiency and economy of the situation being
reviewed, in order to effect improvement.
4. Method-study concerned with “the way in which work is done (i.e., method)”. It is
used to simplify the way to accomplish a work and to improve the method of
production.
Method-study results in a more effective use of material, plant, equipment and
manpower.
It adds value and increase the efficiency by eliminating unnecessary operations,
avoidable delays and other forms of waste.
The improvement of efficiency is achieved through:
1.Present and analysis true facts concerning the situation.
2.To examination those facts critically
3.To develop the best answer possible under given circumstances based on critical
examination of facts.
6. 1. Select : select the work to be studied.
• The job should be selected for the method study based upon the following
considerations:
a) Economical aspect
b) Technical aspect
c) Human aspect
2. Record:
• Record the relevant facts about the job by direct observation
• Recording techniques used for method study are charts and diagrams.
7. Recording techniques for method
study
Charts
Macro motion
charts
1.Operations process chart
2. Flow process chart
3. Two Handed process
chart
4. Multiple activity chart
Micro Motion
charts
Diagrams
Flow
diagram
String diagram
8. 3. Examine:
Examine the way the job is being performed and test its purpose, place,
Sequence and method of performance.
In this step, the information provided by charts and diagrams is critically examined And
screened by asking some searching questions. Like,
PURPOSE for which the activity is done
PLACE at ,, ,, ,, ,, ,,
SEQUENCE in ,, ,, ,, ,, ,,
PERSON by whom ,, ,, ,, ,, ,,
MEANS by which ,, ,, ,, ,, ,,
WITH THE OBJECTIVE OF ELIMINATING/
COMBINING/ REARRANGING/ SIMPLIFYING THE ACTIVITIES INVOLVED IN THE PROCESS.
QUESTIONING TECHNIQUE involves
1. PRIMARY QUESTIONS and
2. SECONDARY QUESTIONS explained below:
9. 9
PRIMARY QUESTIONS
According to the QUESTIONING TECHNIQUE the PRIMARY QUESTIONS
are as follows:
• Purpose-based: WHAT is actually done?
WHY is the activity ELIMINATE
necessary, at all?
• Place-based: WHERE is it being done?
WHY at this place?
• Sequence-based: WHEN is it done? COMBINE or
WHY at that time? REARRANGE
• Person-based: WHO is doing it ?
WHY by this person?
• Means-based: HOW is it being done? SIMPLIFY
WHY in that particular way?
10. 4. Develop:
Develop the most practical, economical, and effective method.
After critical examination of records is complete, it is necessary to transform the
Learning’s into the development of new methods.
Some approaches are:
Eliminate unnecessary activities.
Combine two or more activities. For example, if one uses a combination tool for Two
operations, say, facing and drilling, the total set-up time will reduce.
Re-sequence activities so as to reduce time and effort.
simplify process to reduce number of operations or reduce effort or reduce throughput,
etc.
11. 5.Install:
Install the new method as a standard practice and train the persons involved in
applying it.
A report on new improved method should be prepared. It should include:
• Description of the method.
• Cost of installing the new method, including cost of new equipment and of
relaying
out shops or working areas.
• Diagram of the work place layout.
• Tools and equipment to be used and diagrams of jigs/fixtures etc.
• Executive actions required to implement the new method.
6.Maintain:
Maintain the new method and introduce control procedures to prevent
a drifting back to the previous method of work.
12. Operation process chart
An operation process chart provides the chronological sequence of all operations
and inspections that occur in a manufacturing or business process. Operation
process chart used only two symbols, i.e., operation and inspection.
Combined Activity
Operation and
inspection
Operation and
Transport
13. 13
THE OUTLINE PROCESS CHART
• It uses ONLY TWO SYMBOLS:
&
• It provides an OVERALL PICTURE
of the process / job / task.
• Primarily it is used to show the
sequence of operations &
inspections for a
MANUFACTURING or an
ASSEMBLY kind of jobs.
Outline Process Chart for Repairing a
Punctured Scooter
14. 14
FLOW PROCESSCHART
• It uses ALL THE FIVE SYMBOLS and provides
the total sum details of the process/job under
study.
• A Flow Process chart may be of the following
types:
1.MAN-TYPE in which every symbol is
related to his/her activity only.
2.MATERIAL TYPE in which every symbol is
related to the material of the job or a
document (e.g. in offices)
3. MACHINE/EQUIPMENT.
• Data / information in a flow process chart are
recorded in specifically designed FORM, as
given in the TEXT BOOK / CLASS ROOM.
15.
16. 16
MAN-MACHINE CHART
(MULTIPLE ACTIVITY CHART)
• This kind of process chart records the activities of the
operator as well as the machine on the same chart
against a common time scale.
• Separate vertical columns ( in the form of bars) are
used for both.
• The chart clearly indicates the IDLENESS (or
UTILISATION) of operator as well as the machine.
• On the basis of the recorded events in the chart, one
can rearrange the process so that IDLE-TIME is
reduced, or BETTER UTILISATION of the
operator/machine is achieved.
• It is used for balancing the work between man and
machine ;proper utilization of maintenance crew
/team-activities in mass production.
17.
18. Now, the type of multiple activity charts to be drawn depends upon
the type of job, important types are:
(1) Man-Machine Activity Chart-when one operator is working on one
machine.
(2) Multi-man Activity Chart-when a group of workers are working on a
machine.
(3) Man- Multi machine activity chart- when a single operator is working
on a number of machines.
(4) Multi man- Machine chart- a group of operators working on a common
central machine.
19.
20. 20
METHODS & MOVEMENTS AT THE WORKPLACE
PRINCIPLES OF MOTION ECONOMY
These principles can be helpful in work design, in
reducing the human fatigue and in improving the work
efficiency. According to Barnes, these can be presented
under following THREE subgroups:
1.Principles of motion economy as related to the USE OF
HUMAN BODY
2.Principles of motion economy as related to the
ARRANGEMENT OF THE WORKPLACE
3.Principles of motion economy as related to the DESIGN
OF TOOLS & EQUIPMENT
21. 21
[A] .Principles of motion economy as related to the USE OF
HUMAN BODY
• 1.The two hands should begin and complete
their movements at the same time.
• 2. The two hands should not be idle at the same
time.
• 3.Motions of the arms should be symmetrical
and in opposite direction and should be made
simultaneously.
• 4.Hand and body motions should be made at
the lowest classification at which it is possible
to do the work satisfactorily.
22. 22
CLASSIFICATION OF HAND MOTIONS
CLASS PIVOT BODY MEMBERS MOVED
1 Knuckle Finger (F)
2 Wrist Hand (H) + F
3 Elbow Fore Arm (FA) + H + F
4 Shoulder Upper Arm (UA) +FA+H+F
5 Trunk Torso + UA + FA + H + F
23. 23
Principles : CONTD.
• 5. Momentum should be employed to help the
worker ,but should be reduced to a minimum
whenever it is to overcome by muscular effort.
• 6.Continuous curved motions are to be preferred
to straight line motion involving sudden and sharp
changes in direction.
• 7. Ballistic (free-swinging) motions are faster,
easier, and more accurate than restricted or
controlled motions.
24. 24
Principles CONTD.
• 8.Rhythm is essential to the smooth and automatic
performance of a repetitive operation. The work
should be arranged to permit an easy and natural
rhythm whenever it is possible.
• 9.Work should be arranged so that eye-movements
are confined to a comfortable area, without the
need for frequent changes of the focus.
25. 25
[B].Principles of motion economy as related to the
ARRANGEMENT OF THE WORKPLACE
• 1.Definite and fixed positions/stations
should be provided for all tools and
materials to permit habit formation.
• 2.Tools and materials should be pre-
positioned to reduce searching.
26. 26
CONTD.
• 3.Gravity-feed, bins and containers should be used
to deliver the materials as close to the point of
use as possible.
• 4.Tools, materials, and controls should be located
within the ‘maximum working area’ and as near to
the worker as possible.
[WORKING AREA (WA) may be divided into:
1.NORMAL WA &
2.MAXIMUM WA ]
27. 27
Principles : CONTD.
• 5.Materials and tools should be arranged to permit
the best sequence of motions.
• 6.‘Drop deliveries’ or ejectors should be used
wherever possible, so that operators do not have
to use his/her hands to dispose of the finished
work.
28. 28
Principles: CONTD.
• 7.Provision should be made for adequate lighting
and, a chair of the type of height to permit good
posture should be provided. The height of the
workplace and seat should be arranged to allow
alternate standing and sitting.
• 8.The color of the workplace should contrast with
that of the work and thus reduce the eye-fatigue.
29. 29
[C]. Principles of motion economy as related to the the DESIGN OF
TOOLS & EQUIPMENT
• 1.The hands should be relieved of all work of
“holding” the work-piece where this can be
done by a jig, fixture or foot-operated device.
• 2.Two or more tools should be combined
wherever possible.
• 3.Where each finger performs some specific
movement, as in typewriting, the load should be
distributed in accordance with the inherent
capacities of the fingers.
30. 30
Principles : CONTD.
• 4.Handles such as those on cranks and large screw
divers should be so designed that as much surface
of the hand as possible can come in contact with
the handle. This is specially necessary when
considerable force has to be used on the handle.
• 5.Levers crossbars and hand-wheels should be so
placed that the operator can use them with the
least change in body position and the largest
mechanical advantage.
31. Suggested Workplace Layout
1.NORMAL Working area
2.MAXIMUM Working area
ORT:- Occasionally required tool
CET: Commonly Employed Tool
POA : Place of Assembly
PDA : Place for dropping assemblies
32. 32
Therbligs
• Gilbreth observed that most work done by two hands consists of a few
fundamental motions.
• He called EACH ONE of them as THERBLIG. (name of GILBRETH ,read in
reverse order).
THERBLIG : G I L B R E T H
( read in reverse order)
• At times it may not possible to eliminate completely a macro motion but
unnecessary micro motion can definitely be avoided
• Since the Microsystems is very detailed ,it is simpler to understand what
precisely the worker is doing
• Therbligs colour make the chart meaningful.
• Ex .
Macroscopic Motion Microscopic Motion
Operation of picking away
screw driver
Rich hand for screw driver
(Transport empty )
Grasp the screw driver
(Grasp)
Take away the screw driver
33.
34.
35. SIMO Chart( Simultaneous motion cycle)
It is a graphic representation of an activity and shows the sequence of the therbligs or group of
therbligs performed by body members of operator. It is drawn on a common time scale. In other
words, it is a two-hand process chart drawn in terms of therbligs and with a time scale,
Making the Simo Chart.
A video film or a motion picture film is shot of the operation as it is carried out by the operator.
The film is analyzed frame by frame.
For the left hand, the sequence of therbligs (or group of therbligs) with their time values are
recorded on the column corresponding to the left hand.
The symbols are added against the length of column representing the duration of the group of
therbligs.
The procedure is repeated for the right hand and other body members (if any) involved in
carrying out the operation.
It is generally not possible to time individual therbligs. A certain number of therbligs may be
grouped into an element large enough to be measured as can be seen in
36. Micro motion Study
Dept……………………………………………. Film No……………….
Analysis Sheet
Operation: Finish hand fillings
Charted By……………….
Date……………………………………………………………………………….. Operator…………………
37. SIMO CHART (Corresponding to Fig. 4.12)
Department: …………………………………. Film No…………………
Operation: Finish hand filling
Charted By……………..
Date………………………………………………………………………………. Operator………………..
38. Uses of Simo Chart
From the analysis shown about the motions of the two hands (or other body members) involved
in doing an operation, inefficient motion pattern can be identified and any violation of the
principle of motion economy can be easily noticed. The chart, therefore, helps in improving the
method of doing an operation so that balanced two-handed actions with coordinated foot and
eye motions can be achieved and ineffective motions can be either reduced or eliminated. The
result is a smoother, more rhythmic work cycle that keeps both delays and operator fatigue to
the minimum extent.
