WELCOME TO THE COURSE WORK STUDY (IE 341)

1
WELCOME TO THE COURSEWORK STUDY(IE 341)

• OFFERED BY
• SAYED ALIUL HASAN RIZVI, PhD PROFESSOR
• DEPT OF INDUSTRIAL ENGINEERING
• KING ABDULAZIZ UNIVERSITY, JEDDAH

2
INTRODUCTION

• With increasing complexities of the technological
  world,need to simplify the work system has been
  increasing day by day.
• Work study is an area of knowledge that addresses
  the problem of work simplification with the basic
  objectives of
• PRODUCTIVITY ENHANCEMENT, and
• HUMAN COMFORT SAFETY

3
WORK STYDY HAS MANY OTHER NAMES FOR EXAMPLE

• METHODS ENGINEERING,
• WORK SCIENCE,
• WORK DESIGN,
• JOB ESIGN
• WORK METHODS DESIGN WORK MEASUREMENT
• MOTION TIME STUDY
• Original names were
• Motion study,Time Study
• then, Motion Time Study
• 
  

4
DEFINITION

• It is the systematic study of work systems with
  the purposes of
• Developing the preferred system and Method
• 
  ( with lowest cost)
• 2. Standardizing this system and method
• 3. Determining standard time for the task
• 4. Assisting in training the worker in the
  preferred Method

5
EXPLANATION

• Above stated definition has FOUR parts. However,
  the TWO most important for WORK STUDY are
• 1.MOTION STUDY
• (or Work Methods Design)
• 2. TIME STUDY
• (or Work Measurement)

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ILO DEFINITION

• It is the systematic examination of carrying on
  activities so as to improve the effective use of
  resources and to set standards of performance for
  the activities being carried out.

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LECTURE 3-4CHAPTER 2WORK STUDY
PRODUCTIVITY
8
HUMANS BASIC NEEDS PRODUCTIVITY

• In 1950 world population was 2.5 b
• Now it is of the order of 6.5 b
• 90 increase has occurred in developing
  nations.

9
CONTD.

• Out of these people, more than
• 1 b are below poverty line, struggling for
  the
• BASIC NEEDS which are
• food,
• clothing,
• shelter,
• security,
• health and
• essentials like water, sanitation etc.

10
CONTD.

• For Improving the STANDARD OF LIVING, of its
  citizens, the concerned nation must raise its
  PRODUCTIVITY for economic growth. For any
  organization, its input-output system can be
  represented as follows
• INPUT
  OUTPUT

PROCESS
11

CONTD.

• INPUTS may be in the form of different Ms
• man, material, machine,
  method, management, market, message ( i.e.
  information), moment (i.e. time )
• OUTPUT may be a
• product or
• service.
• PRODUCTIVITY may be defined as follows

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MATHEMATICALLY PRODUCTIVITY
OUTPUT / INPUTTHUS PRODUCTIVITY measures
the extent to which a certain OUTPUT can be
extracted FROM A GIVEN INPUT.It may be noted
that PRODUCTION ( which is number of products)
is different from PRODUCTIVITY.
13

CONTD.

• WORK STUDY IS A TOOL OF PRODUCTIVITY ENHANCEMENT.
  
• It simplifies a job TO REDUCE UNNECESSARY OR
  EXCESS WORK,WASTEFUL USE OF RESOURCESand sets
  up STANDARD TIME for performing that job.

14

CONTD.

• THIS IMPLIES THAT
• THERE IS A DIRECT RELATIONSHIP BETWEEN WORK STUDY
  AND PRODUCTIVITY.
• THUS, BY APPLYING WS PRINCIPLES IF THE COST IS
  REDUCED BY 20, THEN, WE CAN SAY THAT
  PRODUCTIVITY HAS GONE UP BY 20.

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WORK CONTENT OF A JOB

• WORK CONTENT
• It means the amount of work contained in a given
  job/work/product/process.
• It is measured in MAN-HOURS/ WORK-HOURS (effort
  or labor of ONE person for ONE hour), or MACHINE
  HOURS (running of a machine/plant for ONE hour).

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TOTAL TIME OF A JOB

• TOTAL TIME OFA JOB COMPRISES OF
• 1. BASIC WORK CONTENT
• 2. EXCESS WORK CONTENT
• BASIC WORK CONTENT is irreducible minimum
  time required theoretically to produce one unit
  of productIn REAL LIFE WORLD, actual operation
  times are FAR MORE IN EXCESS due to the EXCESS
  WORK CONTENT.

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CONTD.

• EXCESS WORK CONTENT may be due to following
• THREE CATEGORIES of factors
• (i) A-category
• A1 POOR DESIGN FREQUENT
• DESIGN CHANGESA2 WASTE OF
  MATERIALSA3 INAPPROPRIATE QUALITY
• STANDARDS

18

CONTD.

• (ii) B-category
• B1 POOR LAYOUT POOR
• UTILISATION OF SPACEB2 INADEQUATE
  MATERIAL
• HANDLINGB3 FREQUENT STOPPAGES AS
• PRODUCTION CHANGES FROM
• ONE PRODUCT TO ANOTHER

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CONTD.

• B4 INEFFECTIVE METHOD OF WORK
  B5 POOR PLANNING OF INVENTORY
  B6 FREQUENT BREAKDOWN OF MACHINES
  AND EQUIPMENT

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iii) C-categoryC1 ABSENTEEISM AND
LATENESSC2 POOR WORKMANSHIP, ANDC3 ACCIDENTS
AND OCCUPATIONAL HAZARDS
TOTAL TIME OF A JOB
BASIC WORK CONTENT EXCESS
WORK CONTENT ( A B C )

(OR, TOTAL INEFFECTIVE TIME)
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LECTURE 5-8

• CHAPTER 3
• WORK STUDY ,THE APPROACH

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WS IS VALUABLE because By carrying out its
systematic procedures,one can get results as good
as or even better than the less systematic genius
would have been able to achieve in the past.It
is systematic both in the investigation of the
problem and in the development of its solution.
23

CONTD.

• It raises productivity of the plant /unit by
  simply reorganization of the work, with either a
  nominal or no extra input.It sets the
  performance standards on which the effectiveness
  of the production planning and control depends.

24

CONTD.It contributes to
human safety by providing safer methods of work,
and allows for better working conditions by
exposing the hazardous situations.Its
application starts providing savings immediately,
and continues till the operation continues.
25

CONTD.

• It is a tool that can be used every where, be it
  industrial or non-industrial environment.
• It is easy and relatively cheaper in its
  application.It is an excellent weapon for
  starting an attack on the inefficient system.
• HOWEVER, WS SPECIALISTS SHOULD APPLY IT
  TACTFULLY, SO THAT WORKERS REMAIN CO-OPERATIVE
  WHILE STUDIES ARE CONDUCTED IN THE PLANT.

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TECHNIQUES OF WORK STUDY These
are1. METHOD STUDY is the systematic recording
and critical examination of ways of doing things
in order to make improvements. THUS it
simplifies the job and develops more economical
method of doing it.2.WORK MEASUREMENT is the
application of techniques designed to establish
the time for a qualified worker to carry out a
task at a defined rate of working.THUS it
determines how long it should take to carry out
the work.
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BASIC PROCEDURE OF WS comprise of following

STEPS1.SELECT the
job/task/process to be studied.2.RECORD all
the relevant data/facts about the
selected job.3.EXAMINE the recorded
facts critically by challenging
its purpose, place, sequence, person, and
method.4.DEVELOP new
methods,as alternative methods, of
doing the selected job. 5.EVALUATE
results of different alternative solutions.
6.DEFINE the new method and present it to
the concerned people.
7.INSTAL the new method and provide
training to the concerned
staff . 8.MAINTAIN the new standard practice
and establish control
procedures.
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ACCORDING TO BARNES Since Methods Engineering is
a form of CREATIVE PROBLEM SOLVING, THE GENERAL
PROBLEM SOLVING PROCESSES can be employed in WS
also. Accordingly, following FIVE STEPS can
be used 1.Problem definition Statement of
the purpose/goal 2. Analysis of the problem
Fact-recording no evaluation 3.Search for
possible solutions Finding several

alternative solutions. 4. Evaluation of
alternatives Examining which
alternative meets the goal/criteria most, in
order to evolve the preferred
solution. 5. Recommendation for action
Communicating the details ,related to the
preferred method to all concerned.
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LECTURE 9-10

• CHAPTER 6
• METHOD STUDY JOB SELECTION

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STEP I JOB/TASK/PROCESS SELECTION

• It involves following considerations
• 1. ECONOMIC CONSIDERATIONS
• 2. TECHNOLOGICAL CONSIDERATIONS and
• 3. HUMAN CONSIDERATIONS

31

Contd.

• 1.ECONOMIC CONSIDERATIONS
• Cost effectiveness i.e. to check whether or
  not the WS application would pay. For this,
  key-profit giving/ costliest operations with
  largest waste/scrap should be attacked first.
  Next bottleneck operations, repetitive
  operations, repeated material handling operations
  should be studied. For locating most important
  operations, PARETO ANALYSIS could be used.

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2.TECHNICAL/TECHNOLOGICAL CONSIDERATIONS

• The analysis involves application of WS for
  the selection of the operations/processes where
  new technology e.g. automation/ robotisation
  should be introduced.

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3.HUMAN CONSIDERATIONS

• Analysis involves location of those
  operations which present the sources of
  dissatisfaction and/or annoyance to the workers
  due to fatigue or monotony or unsafe environment
  or a work which is clumsy in nature.

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LECTURE 11-12CHAPTER 7RECORDING THE FACTS
DIAGRAMS CHARTS
35
STEP II RECORDING THE FACTS

• Related to the existing process/ job ALL THE
  FACTS should be recorded ACCURATELY.
• TOOLS OF FACT-RECORDING are
• (A) CHARTS, which may be of two types
• (i) Based on SEQUENCE
• (a) Outline Process Chart
• (b) Flow Process Chart
• (c) Two-Handed Chart ( or Operation
• Chart / Left Hand Right
  Hand chart)

36

CONTD.

• (ii ) Based on TIME scale
• (a) Multiple Activity Chart
• (b) SIMO ( SImultaneous MOtion) Chart
• (B) DIAGRAMS which may be of the following
  types
• Flow diagram, String Diagram, Travel Chart,
• Cyclegraph, Chronocyclegraph,

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PROCESS CHART SYMBOLS

• ASME has recommended FIVE standard symbols to be
  used on
• 
  Process Charts, given below
• OPERATION Main steps of the
• task /job involving
  modification /change.
• 2. INSPECTION Checking
  quality / quantity.
• TRANSPORTATION For movement of
• 
  persons/materials.
• DELAY (TEMPORARY) For waiting
  time of
• 
  operators or materials.
• 5. STORAGE (PERMANENT DELAY) For
• controlled storage involving
  authorized
• issue/receipt of material etc.
• NOTE FOR TWO PARALLEL EVENTS, BOTH ARE
• SHOWN IN ONE JOINT OR COMBINED
  SYMBOL e. g.
• operation inspection ,jointly are
  shown
• by symbol, indicated in the figure.

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THE OUTLINE FLOW 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.

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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) or a
• machine/equipment.
• Data / information in a flow process chart are
  recorded in specifically designed FORM, as given
  in the TEXT BOOK / CLASS ROOM.

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LECTURE 13-14CHAPTER 7 (CONTD)
41
STEP III CRITICAL EXAMINATION

• The facts recorded in the Flow Process Chart are
  now EXAMINED CRITICALLY
• by applying the
• QUESTIONING TECHNIQUE,
• which involves the following SEQUENCE

42
CONTD.

• 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

43
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?
• WHY at that
  time? COMBINE or
• Person-based WHO is doing it ?
  REARRANGE
• WHY by this
  person?
• Means-based HOW is it being done?
  SIMPLIFY
• WHY in that
  particular way?

44
SECONDARY QUESTIONS

• Corresponding to each answer obtained through the
  PRIMARY QUESTIONS further questions are raised to
  explore about the
• ALTERNATIVES
• i. e. alternate purpose, place, sequence,
  person means.
• This methodology makes use of the SECONDARY
  QUESTIONS given as follows

45

Contd.

• WHAT ELSE might be done?
• WHERE ELSE might it be done?
• WHEN ELSE might it be done?
• WHO ELSE might do it?
• HOW ELSE might it be done?
• BY ANSWERING THE PRIMARY SECONDARY QUESTIONS WE
  USE THE SYSTEMATIC CRITICAL EXAMINATION IN ORDER
  TO EVOLVE A BETTER METHOD OF DOING THE WORK.

46
Contd.

• AS A RESULT, ONE CAN DEVELOP A BETTER METHOD IN
  LIGHT OF THE OBTAINED ANSWERS TO THE FOLLOWING
  QUESTIONS
• WHAT should be done?
• WHERE should it be done?
• WHEN should it be done?
• WHO should do it ?
• HOW should it be done?

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LECTURE 15-17CHAPTER 8RECORDING
MOVEMENT OF WORKERS/MATERIALS
48
RECORDINGMOVEMENT OF WORKERS/
MATERIALS

• TOOLS USED FOR THIS PURPOSE ARE
• STRING DIAGRAM
• FLOW DIAGRAM
• TRAVEL CHART

49
STRING DIAGRAM

• IT IS A SCALE PLAN OR MODEL ON WHICH A THREAD OR
  STRING IS USED TO TRACE AND MEASURE THE PATH OF
  WORKERS/ MATERIALS DURING A SPECIFIED SEQUENCE OF
  EVENTS.
• LENGTH OF THE THREAD/STRING MEASURES THE DISTANCE
  MOVED.

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FLOW DIAGRAM

• It is a FLOOR-PLAN showing the path of travel of
  the operator or the material, through the plant.
• It ALSO indicates the direction of travel by
  means of arrows, drawn on the diagram.

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TRAVEL CHART ( or, FROM-TO CHART)

• It is a tabular record of quantitative data about
  movement of workers/materials/equipment between
  any number of places over a given period of time.
  It is always in the form of a SQUIRE, having
  within it the squires.
• EACH SMALL SQUIRE REPRESENTS A STATION.
• Along the TOP, squires from left to right
  represent the stations FROM where movement or
  travel occurs.
• Along those DOWN THE LEFT HAND, the squires
  represent the stations TO which the movement is
  made.

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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.

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LECTURE 18-24

• CHAPTER 9
• METHODS MOVEMENTS AT THE WORKPLACE

54
METHODS MOVEMENTS AT THE WORKPLACEPRINCIPLES
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

55
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.

56


Principles Contd

• 4.Hand and body motions should be made at the
  lowest classification at which it is possible to
  do the work satisfactorily.
• The term CLASSIFICATION OF HAND
• MOTION is explained as follows

57
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) FAHF
• 5 Trunk Torso UA FA H F

58
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.

59
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.

60
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.

61

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 explained below

62
Cotd.

• Normal Working Area (WA)
• ( Finger wrist elbow) Movement
• MOST
  CONVENIENT ZONE
• Edge
• of bench
  operator
• 
  operator
• Maximum WA (Shoulder Movement)
  

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DIMENSIONS FOR SEATED TASKS

• 1.SEAT HEIGHT should be adjustable
• (
  range36-45 )
• 2. WORK SURFACE HEIGHT should be around
• elbow
  level (range65-72 cm)
• 3.LEG CLEARANCE 40 cm at knee level
• 60
  cm for the feet
• 4.THIGH CLEARANCE 20 cm minimum
• 5.WORK SURFACE THICKNESS 5cm max.

64
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.

65

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.
  

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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.

67
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.

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TWO-HANDED PROCESS CHART (OPERATION
CHART/LEFT-HAND RIGHT-HAND CHART)

• It shows the activities of the two hands in
  relation to one another.
• ACCORDING TO BARNES
• It uses ONLY TWO SYMBOLS
• Small circle for TRANSPORTATION
• Big circle for OPERATION.
• ACCORDING TO ILO
• It uses ALL process chart symbols EXCEPT
  INSPECTION
• After studying a few cycles recording is done.
• ONLY ONE HAND is charted AT A TIME.

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FUNDAMENTAL HAND MOTIONS

• 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)

70

contd.

• Today we have 17 Therbligs as follows
• Search, select,
  grasp, transport empty,
  transport loaded, hold,
  release load position,
  preposition, inspect,
  assemble, disassemble, use,
  unavoidable delay avoidable delay,
  plan, rest for
  overcoming fatigue.
• THESE ARE USED IN MICROMOTION STUDIES (FACTS
  RECORDED ON FILMS)

71
MICROMOTION STUDIES

• Operations with very short cycles repetitive
  cycles need greater details to analyze it for
  saving motions and effort( i.e. planning for
  lesser fatigue). This goal can be achieved
  through Micro-motion Studies.
• MICRO means small. Thus here we study the
  motions in terms of THERBLIGS.

72

CONTD.

• Such a study involves the use of
• FILM and VIDEO
  when operator performs the job.
• Later on the film/video can be run slowly THROUGH
  A PROJECTOR and
• Frame by frame analysis of the work can be
  carried out.
• Film provides greater flexibility of filming and
  playback speeds WHEREAS video is easier in use.

73

Contd.

• STEPS
• 1. Filming the job
• 2. Analysis of the film,
• 3. Presenting DATA/FACTS
• graphically through
• SIMO chart.
• (SImultaneous Motion Chart)

74

CONTD.

• EQUIPMENT
• Camera, Film,
  Micro-chronometer,
• Exposure meter, Flood lights,
• Reflectors, Tripod,,
  Projector etc.
• OR,
• VIDEOCAMERA plus its
• accessories for filming
• operation.

75
CONTD.

• ADVANTAGES OF MICROMOTION STUDIES OVER DIRECT
  OBSERVATION.
• Greater details are made availalble
• More accurate
• Easier in data collection
• Better for record keeping
• Help in work study personnel's development

76
FILM ANALYSIS

• Film is run on projector,
• Details of the work-cycle are identified in terms
  of THERBLIGS, first for
• Left hand
• and then for
• Right hand,
• TIME ( in WINK) is noted from the
• Chronometer readings of the film for each
• therblig.
• 1 WINK (1/2000) OF A MINUTE

77

CONTD.

• With these data SIMO (Simultaneous Motion) chart
  is made as shown below
• LH Activities Therblig Time
  Therblig RH Activity

78
MEMOMOTION ANALYSIS

• It was introduced by MUNDEL.
• It is a special type of micro-motion study in
  which activities are FILMED AT MUCH SLOWER SPEED
  (60 to 100 frames per minute) i.e. at longer
  intervals than normal (intervals being between
  0.5 to 4 s).
• Thus a general pattern of movements can be
  obtained and avoidable motions can be
  identified.

79

contd.

• STEPS Study the operation to be filmed
• Prepare the film Analyze the film
  
• Develop a better method.
• ADVANTAGES More economical (less film consumed)
  and Long sequence of activities can be recorded
• APPLICATIONS
• Team-work studies
• Material flow studies ( e.g. baggage
• movement at the
  airports )
• Long cycle job studies
• Study of artificial limbs motions etc

80
CYCLEGRAPH

• It was introduced by Gilbreth.
• It is a photographic record of the path of
  movement of the operator doing a job.
• Little source of light (bulb) is attached to the
  hand or finger or any other body part, whose
  motions are to be analyzed. When he/she performs
  the operation and photograph is taken
  continuously, the path of motions is recorded on
  the film as CONTINUOUS STREAK OF LIGHT as shown
  below
• 
  OPERATO R
  

81
CHRONOCYCLEGRAPH

• It is a special type of cycle-graph in which the
  light source (bulb) is suitably INTERRUPTED
  ELECTRICALLY so that the path of motion in the
  photograph appears as a SERIES OF PEAR-SHAPED
  SPOTS instead of continuous streak of light as
  shown below
• 
  PEAR-SHAPED SPOTS
• MOTION DIRECTION
• The pointed end of the pear shows the direction
  of movement.
• More elongated and spaced pear-spots indicate
  higher speed of operation..
• It helps in studying the complex and restricted
  motions also.