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Routine Job System in Chart - PowerPoint

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					Workplace layout and economy
                       Introduction

• So far we have been looking at factory layout and movement
  of workers, material on the shop-floor.
• We studied the theory of analysis for movement of both, the
  material and the worker.
• We recall the method of analysis same in both cases.
• We go in to little more detail and look at individual workspace
  – office desk, table.
• Once again, we use similar method of analysis.




                                                                2
                     Introduction

While analyzing material and worker movement on shop floor,
  main concern was:
• Better utilization of existing plant and machinery though
  elimination of unnecessary idle time,
• The more effective operation of processes and
• The better utilization of services of labor through the
  elimination of unnecessary and time-consuming movement
  within the working area of factory, department or yard.




                                                              3
                       Introduction

However, while studying the operator at the workplace,
• The main goal is to study the way (s)he applies the efforts and
  amount of fatigue resulting from the manner in which worker
  performs the tasks.
• Objective is to improve worker productivity.




                                                                    4
                 Process of analysis
First step: make sure that the job to be analyzed is in fact
   necessary and is done as it should be done.
The questioning technique needs to address:
• Purpose: to ensure that the job is necessary;
• Place: to ensure that it is being done where it should be done;
• Sequence: to ensure that it is in its right place in the sequence
   of operations;
• Person: to ensure that it is being done by the right person.
After verification that the job can not be eliminated, it is possible
   analyze further.


                                                                        5
                Process of analysis

• Second step: questioning technique to ascertain:
Means: by which the job is being done, and to simplify them as
  much as is economically justified.




                                                                 6
        Principles of motion economy

• Also called “the characteristics of easy movement” as per the
  British Standards Glossary of Terms in Work Study.
• Developed by Frank Gilbreth, the founder of motion study.
• Frank Gilbreth is acknowledged as the pioneer of the field of
  scientific management. A field later made popular by F.W.
  Taylor.
• Fine-tuned by Prof. Ralph M. Barnes (in his book Motion and
  Time Study: Design and Measurement of Work).




                                                                  7
                      Gilbreth story

• As a young building contractor, he found ways to make
  bricklaying faster and efficient process.
• Along with his wife Lillian Gilbreth, he studied the work
  habits of manufacturing and clerical employees in all sorts of
  industries to find ways to increase output and make their jobs
  easier.
• Gilbreths reduced all the motion of hand to a basic set of 17
  motions.
• They called it “therbligs.”
• One of the first to study workplace scientifically: first use of
  motion picture camera calibrated in fractions of minutes.
                                                                     8
                    Gilbreth story

• Emphasized the need to constantly question the processes on
  the shop floor and improve continuously (much before the
  continuous quality improvements philosophy was developed).
• Today, use of therbligs is a very standard way of analyzing
  and economizing the movements at the workplace.
• Has strong connections with ergonomics.




                                                                9
                    Gilbreth story
Difference in philosophies of Gilbreth and F.W. Taylor:
• Taylor approach focuses on time measurement; whereas
  Gilbreth focuses on work measurement.
• Taylor’s concern was the reduce the time to complete a
  process; Gilbreth sought to make processes more efficient by
  reducing the motions involved.
• Reduction of unnecessary movements were perceived by
  workers as beneficial to them; whereas Taylor’s approach was
  perceived as a management compulsion.




                                                             10
        Principles of motion economy
•    Principles concerning the economy of movements which
     have been developed from direct experimentation and form
     a good basis for the development of improved methods at
     the workplace.
•    Classified as three main types:
A.   Use of human body,
B.   Arrangement of the workplace,
C.   Design of tools and equipment.




                                                                11
             Use of the human body
When possible –
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 except
   during periods of rest.
3. Motion of arms should be symmetrical and in opposite
   directions and should be made simultaneously.
4. Hand and body motion should be made at the lowest
   classification at which it is possible to work satisfactorily.
5. Momentum should be employed to help the worker, but
   should be reduced to a minimum whenever it has to be
   overcome by muscular effort
                                                                    12
        Classification of movements

Class    Pivot      Body parts moved

1        Knuckle    Fingers
2        Wrist      Hand + above

3        Elbow      Forearm + above
4        Shoulder   Upper arm + above

5        Trunk      Torso + above




                                        13
             Use of the human body
6.   Continuous curved movements are to be preferred to
     straight-line motion involving sudden and sharp changes in
     direction.
7.   Free-swinging movements are faster, easier and more
     accurate than restricted or controlled movements.
8.   Rhythm is essential to the smooth and automatic
     performance of a repetitive operation.
9.   Work should be arranged so that eye movements are
     confined to a comfortable area, without the need for frequent
     changes of focus.



                                                                14
            Arrangement of workplace
1.   Definite and fixed station should be provided for all tools and
     materials to permit habit formation.
2.   Tools and materials should be pre-positioned to reduce
     searching.
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.
5.   Materials and tools should be arranged to permit the best
     sequence of motions.
6.   The color of workplace should contrast with that of the work
     and thus reduce eye fatigue.
                                                                  15
           Arrangement of workplace

7.   “Drop deliveries” or ejectors should be used wherever
     possible so that the operator does not have to use his hands to
     dispose of the finished work.
8.   Provision should be made for adequate lighting, and a chair
     of the type and height to permit good posture should be
     provided.
9.   The height of the workplace and seat should be arranged to
     allow alternative standing and sitting.




                                                                  16
        Design of tools and equipment
1.   The hand 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 specific movements, the load
     should be distributed in accordance with the inherent
     capacities of the fingers.
4.   Handles such as those on cranks and large screwdrivers
     should be designed so as to permit as much of the surface of
     the hand as possible to come in contact with 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 greatest “mechanical advantage.”

                                                                  17
          Two-handed process chart

• A process chart in which the activities of a worker’s hands are
  recorded in their relationship to one another.
• Specialized form of process chart because it shows the two
  hands (sometimes feet also) of the operator moving or static in
  relation to one another.
• Time scale can also be included.
• Inclusion of time scale facilitates analyses of what the two
  hands are doing at any given moment opposite to one another.
• Used for repetitive operations, when one complete cycle of the
  work will be recorded.
• Recording is much more detailed than other charts.
                                                               18
           Two-handed process chart
• Symbols used mean different in the two-handed process chart.
Operation – Activities of grasp, position, use, release etc. of tool,
  component, or material.
Transport – Movement of hand (or limb) to or from the work, or
  a tool, or material.
Delay – Denote time during which the hand or limb being charted
  is idle (other hand may be in use).
Hold (Storage) – Activity of holding work, tool, or material – the
  hand is holding something.

• The symbol for “Inspection” is not much used because
  typically inspection activity can be called “Operations.”
                                                                   19
          Two-handed process chart

• Enables the work study person to gain intimate knowledge of
  the details of the job.
• Enables to study each element of the job by itself and in its
  relation to other elements.
• From this study, ideas for improvements are developed.
• The best method is generally that which requires the fewest
  movements.
• The chart can be applied to assembly, machining and even
  clerical jobs.



                                                                  20
          Two-handed process chart
• Study the operation cycle a few times before starting to record.
• Picking up or grasping a fresh part at the beginning of a cycle
  of work is a good point to start the record.
• Start with the hand that handles the part first or the hand that
  does the most work.
• Only record action on the same level when they occur at the
  same moment.
• Actions which occur in sequence must be recorded on the
  chart at different horizontal levels.
• Check the chart for time relation of the hands.
• Record everything that the operator does.
• Avoid combining operations and transports or positionings,
  unless they occur at the same time.
                                                                21
                 Micromotion study
• Applicable for operations with very short cycles which are
  repeated thousands of times.
• Goes into greater details to determine where movements and
  efforts can be saved and to develop the best possible patterns
  of movements.
• Enables operators to perform the operation repeatedly with
  minimum effort and fatigue.
• The technique used for this typically involves filming the
  operation and hence is known as micromotion study.
• Examples of operators studied could be cashier in the bank –
  routine job of taking payment slips from customer and issuing
  cash!

                                                               22
                 Micromotion study

• Based on the idea that human activity can be divided into
  movements or group of movements (therbligs) according to
  the purpose for which they are made.
• The therbligs cover movements or reasons for the absence of
  movement.
• Each therblig has specific color, symbol and letter for
  recording purposes.
• Therbligs refer primarily to motions of the human body at the
  workplace and to the mental activities associated with them.



                                                                  23
                  Micromotion study

• They permit a much more precise and detailed description of
  the work than any other method described.
• Considerable practice is required in identification of therbligs
  before they can be used for analysis with confidence.




                                                                     24
         Use of films in method study
Main advantages of films over visual methods are:
• Permit greater detailing than eye observation;
• Provide greater accuracy than pencil, paper and stop watch;
• More convenient;
• Provide a positive record;
• Help in the development of the work study person.




                                                                25
                       SIMO chart

• SImultaneous MOtion cycle chart.
• Based on film analysis, used to record simultaneously on a
  common time scale the therbligs or group of therbligs
  performed by different parts of the body of one or more
  workers.
• Micromotion form of the man type process flow chart.
• Primarily used for operations of short duration, often
  performed with extreme rapidity.
• At times, it is necessary to compile them from films made of
  the operation which can be stopped at any point or projected in
  slow motion.
                                                               26
                      SIMO chart

• The movements in SIMO chart are recorded against time
  measured in “winks.”
• 1 wink = 1/2000 minute.
• These are recorded by “wink counters” placed in such a
  position that it can be seen rotating during the filming.
• Some SIMO charts are drawn up listing the fingers used, wrist,
  lower and upper arms.
• The corresponding therblig symbols are used for the activity.




                                                              27
           MEMO motion photography
• A camera is placed with a view over the whole working area.
• Takes pictures at a rate of one or two per second (as against
  regular 24 frames per second).
• A 10 minute activity can be compressed in one minute film
• Very rapid survey of the general pattern of movements may be
  obtained.
• From the activity, larger movements giving rise to wasted
  effort can be detected and eliminated.




                                                             28
                      Cyclegraph

• A record of path of movements, usually traced by a continuous
  source of light on a photograph.
• The path of movements of a hand, may be recorded on a
  photograph in this way if the worker is asked to wear a ring
  carrying a small light which may make the trace on the
  photograph.
• If the purpose is to record the path over which the worker
  moves, this light may be attached to the helmet.




                                                             29
                Chrono-cycle-graph
• A special form of cyclegraph in which the light source is
  suitably interrupted so that the path appears a series of pear-
  shaped dots.
• The pointed end of the pear indicates the direction of
  movement.
• The spacing indicates the speed of movement.
• The application of these recording techniques is limited
  compared to the process flow charts and diagrams mentioned
  earlier.




                                                                    30
                        P.M.T.S.
Predetermined Motion Time System chart.
• There are several PMTS codes, all of which set out the basis
   human motions and qualifying conditions with corresponding
   time values.
• Breaking down the motions is similar to therbligs.
• Founded on the premise that if an activity is broken down in
   sufficient detail into basic motions, times established
   elsewhere for these basic motions can be applied.
• Thus, standard time required to perform an activity can be
   calculated.
• Use of PMTS requires lot of training.



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