Time And Motion Study.docx

WorkStudy Edit Work Study Definition by ILO : Is a generic term for techniques, particularly method study and work measurement, which are used for the examination of human work in all its contexts, and which lead systematically to investigation of all the factors which affect the efficiency and economy of the situation being reviewed, in order to seek improvements.

Work study investigates the work done in an organization and aims at finding the best and the most efficient way of utilizing the available resources (man, material, money and machinery) to achieve best possible quality work in minimum possible time. - which involves least possible time and causes least possible fatigue to the worker

Method study or Motion study

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Method Study is the systematic recording and critical examinaton of existing and proposed ways of doing work, as a means of developing and applying easier and more effective methods and reducing costs. Work StudyAreas of Application The application of methods engineering may be required in a variety of circumstances. It ranges from the design of a new plant, to the design of a new product, to the design of a new process, to the improvement of an existing process, to the improvement of an existing workplace. Wherever work is being done, methods engineering is a desirable function to ensure that the work is being done in the easiest, safest, and most productive way. Origin of Methods Engineering Methods engineering grew out of the pioneering developments of the Gilbreths (Frank B, and his wife, Lillian M.) who developed many of the tools of “motion study” as a part of formulation a systematic approach to the analysis of work methods. Frank B Gilbreth first become interested in methods analysis as an outgrowth of his observations of brick-laying. Gilbreth, who in 1885 was employed as an apprentice bricklayer, soon observed that a journeyman bricklayer used one set of motions when laying bricks slowly, another set

when working at average speed, and still a different set when working at rapid speed. As a result of his observations, he invented an adjustable scaffold and developed a set of motions that greatly increased the number of bricks that could be laid in a day. Organization for Methods Engineering As indicated previously, methods engineering is a necessary function to ensure that the most efficient methods are being used. This activity is most frequently performed by industrial engineers; however, all engineers should be concerned with work methods. The engineers may be assigned to a central methods engineering or industrial engineering department or may be assigned on a decentralized basis to specific operating departments. Some multiplant companies maintain both a central industrial engineering group to work on problems common to many plants and also assign engineers to each plant to work on projects pertinent only to that plant.

Approach to Methods Design Charles E. Geisel States that in order to design a system (method) thoroughly, eight elements must be considered. 1. Purpose: The function, mission, aim or need for the system. 2. Input: The physical items, people, and/or information that enter the system to be processed into the output. 3. Output: That which the system produces to accomplish its purpose, such as finished steel, assembled toasters, boxes, and so forth. 4. Sequence: The steps required to convert, transform, or process the input to the output. 5. Environment: The condition under which the system operates, including physical, attitudinal, organizational, contractual, cultural, political, and legal environment. 6. Human agents: The people who aid in the steps of the sequence without becoming a part of the output. 7. Physical catalysts: The equipment and physical resources that aid in the steps of the sequence without becoming part of the output. 8. Information aids: Knowledge and information resources that aid in the steps of the sequence without becoming part of the output. To ensure that the optimum method is found, a systematic approach to methods design, superior to the use of a ‘hit or miss’ method, is used. Stated in simplest form, this approach consists of the following steps: 1. Analyze the problem: Identify the problem and then secure all known information about it through the use of appropriate analysis techniques.

2. Question are present method. If a method presently exists, question the details of the known information to determine the principles violated. 3. Synthesize a proposed method: Formulate a proposed method for performing the work, embodying all the principles of sound methods engineering. 4. Apply the proposed method: Standardize and apply the new method.

Tools for Methods Analysis Name of Chart Where Used Flow Process Macro analysis; shows big picture of a production process operation by operation; may be performed by visual observation. Operation – right and left- Micro analysis: Shows steps performed by a worker within hand an operation; may be performed by visual observation. Simo- simultaneous Fine micro analysis; uses threbligs for a very detailed motion chart analysis of human motions; usually makes use of videotape or motion pictures. Multiple activity – worker Macro; may involve machines or several workers and time and machine or crew is of significance, may be performed by visual observation and/or videotape.

Process Chart A flow process chart is a graphic symbolic representation of the work performed or to be performed on a product as it passes through some or all of the stages of a process. Typically, the information included in the charts is quantity, distance moved, type of work done by symbol with explanation, and equipment used. Work times may also be included. Right and Left – Hand Operation Chart Symbol Name Activities Represented Operation Modification of object at one workplace. Object may be changed in any of its physical or chemical characteristics, assembled or disassembled, or arranged for another operation, transportation, inspection, or storage. Transportation Change in location of object from one place to another Inspection Examination of object to check on quality or quantity characteristics Delay Retention of object in a location awaiting next activity.

Not authorization is required to perform the next activity. Storage Retention of object in location in which it is protected against unauthorized removal.

Multiple Activity Chart

In those operations involving the combination of a person and a machine, a person and several machines, or any combination of people and machines where delays are prevalent, the multiple activity chart provides a convenient technique for analyzing the combined activity. Very often the objectives of this type of analysis are to attain the maximum utilization of a machine, to attain the optimum person to machine relationship, or to bring about the best balance of crew activity. For this reason, the time factor is an important consideration and necessitates the use of a graphical representation involving time. Use of Videotape In the past, the experienced methods engineer found that one of the most important aids was the use of motion pictures. There are many situations in which it is difficult to observe all of the action taking place because of the high speed of activities or the complexity of the operation. Having observed slow-motion motion pictures, we are familiar with the fact that one can take motion pictures at high speed and then, by projecting them at normal speed, slow the action down. By the same token, we can take the pictures at slow speed and project them at what appears to be high speed. In using motion pictures, methods engineers may have had several objectives in mind. First and foremost, they may have wanted a permanent record of the work as it was being performed. Or they may have wished to use the film for analysis purposes, commonly referred to as “micromotion” or “memomotion” studies, discussed in some detail in sections that follow. Micromotion Study Micromotion study, which was originated by Frank B. Gilbreth, is one of the most exacting forms of work analysis available for job improvement. It is an analysis technique making use of motion pictures (or videotape) taken at a constant and known speed. The film becomes a permanent record of both the method being used and the time consumed in doing the work.

Although micromotion study formerly made use of motion pictures, very few companies today are using them. As indicated earlier, videotape equipment has been developed so extensively that it has virtually supplanted the use of the motion picture camera. Further it is so cheap and easy to use that it makes the older approach archaic. Micromotion study provides a valuable technique for making minute analyses of those operations that are short in cycle, contain rapid movements, and involve high production over a long period of time. Thus it is very useful in analyzing operations such as the sewing of garments, assembly of small parts and similar activities.

Memomotion Study Before leaving the general area of micromotion study, let us touch briefly on memomotion study. Memomotion study, which was originated by M.E. Mundel, is a special form of micromotion study in which the motion pictures or videotape are taken at slow speeds. Sixty and one hundred frames per minutes are most common. Memomotion study has been used to study the flow and handling of materials, crew activities, multiperson and machine relationships, stockroom activities, department store clerks, and a variety of other jobs. It is particularly valuable on long-cycle jobs or jobs involving many interrelationships. In addition to having all of the advantages of micromotion study, it can be used at relatively low film or tape cost (about 6% of the cost at normal camera speeds) and permits rapid visual review of long sequence of activities. Principles of Motion Economy Through the pioneer work of Gilbreth, Ralph M. Barnes and other investigators, certain rules for motion economy and efficiency have been developed. Some of the more important of these principles are the following: 1. The movements of the two hands should be balanced and the two hands should begin and end their motions simultaneously. 2. The hands should be doing productive work and should not be idle at the same time except during rest periods. 3. Motions of the hands should be made in opposite and symmetrical direction and at the same time. 4. The work should be arranged to permit it to be performed with an easy and natural rhythm. 5. Momentum and ballistic-type movements should be employed wherever possible in order to reduce muscular effort. 6. There should be a definite location for all tools and materials, and they should be located in front of and close to the worker. 7. Bins or other devices should be used to deliver the materials close to the point of use.

8. The workplace should be designed to ensure adequate illumination, proper workplace height, and provision for alternate standing and sitting by the operator. 9. Wherever possible, jigs, fixtures, or other mechanical devices should be used to relieve the hands of unnecessary work. 10. Tools should be prepositioned wherever possible in order to facilitate grasping them. 11. Object should be handled, and information recorded. Only once.

Job Enlargement and Enrichment This has led to the contention of a number of social scientists that hobs need to be enlarged or enriched. Feedrick Herzberg, one proponent of job enrichment, feels that the purpose of job enrichment should be to eliminate the undesirable characteristics of highly repetitive, specialized work by enlarging it to include: 1. Greater variety of knowledge and skill 2. Giving a person a complete natural unit of work (module, division, area, etc.) 3. More complex utilization of the important cognitive and motor abilities possessed by the worker. 4. More freedom and responsibility in the performance of the tasks at hand. Among the principles that commonly are applied in job enrichment programs, the following are attended to by one large company. 1. Ensure that there is variety in the job content. 2. Include in the work situation an opportunity for the worker to grow and learn. 3. Provide an opportunity for each worker to have knowledge of the part that his or her job plays in the total manufacturing process required to produce the product. 4. Design the work so that it has meaning to the worker and provides pride in performance to the worker. 5. Ensure that the work is reasonably demanding and functionally inclusive. Provide for self-direction of the work and for the checking of quality of output. Value Analysis As a part of the approach to methods improvement, the methods engineer should question the impact of the design of the parts, the materials used, and the equipment used on the productivity of operations. That is, the methods engineer should be thoroughly familiar with value analysis, an activity that is closely both to the methods improvement programs and to purchasing and that is being used extensively in industry

and the government. Value analysis is an objective study of every item of cost in every component part, subassembly, or piece of equipment. This includes a study of the design, the material, and the process in a continual search for other possible materials and new processes. Value analysis involves the evaluation of an items function and relates its effect to the end product. The purpose is to attempt to ensure that every element of cost contributes proportionately to the function of the item.

Social and Economic Effects of method Study As pointed out at the beginning of this chapter, modern industry is constantly searching for better methods. When a business ceases to move forward, it will lost ground and may eventually fail. It is for this reason that the major companies have organized industrial engineering groups, work simplification and value analysis programs, suggestion systems, quality circles, and other methods of achieving reduced costs of manufacturing their products. One of the consequences of these programs has been increased mechanization, which, in turn, has led to the production of more and more goods per work hour. Among the long-range benefits derived from this increased output have been higher real wages, an improved standard of living, a shorter work week, and a reaction of the physical rigors of the job. --

Work Measurement or Time study

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Method Study – Systematic recording & critical examination of the way of doing a work as a mean for developing more effective methods & reducing costs. Work Measurement – Establishing the time required by a qualified worker to carry out a specified job at a defined level of performance Steps in Method Study - : Select

job or process to be studied All the details concerning Record job Examine Recorded facts Define New method Install New method Maintain New method

Develop Most economical method

Recording Techniques - : 1. Process Charts 1. Outline Process chart (or operation process chart) 2. Flow Process chart (Man type; Material type; Equipment type) 3. Multiple activity chart 4. Two handed process chart (or Left hand-Right hand chart) 5. SIMO chart (Simultaneous Motion Cycle chart) 2. Diagrams 1. Flow diagram 2. String diagram 3. Cyclegraph 4. Chronocyclegraph 3. Models i) Outline Process Chart – Gives bird’s eye view of the process; considers only main operations and inspections ii) Flow Process Chart – Detailed version of operation process chart shows the "OTIDS" Operation (transforms or performs work that the customer may see as Value which is the product or service Function at a Cost); Transport/Move; Inspection/Check; Delay/Wait and Store/File. Recent "OTIDS" have adde anoth D being Decision to become "OTIDDS". The use of "Value Stream Maps" in "Lean" (John Krafcik a research student at MIT in late 1980's) are enhanced for each major step in the Value Stream by using the Flow Process Chart to provide more details on the value and non-value activities in the Stream. Value Analysis/Value Engineering and Process Failure Mode and Effect Analysis techniuques in the Automotive qualkity and technical specificvation (ISO TS16949:2002) and Boeing Aircraft Corporation Quality Tools Manaul all use Flow Process Charts Person type – Sequence of activities performed by worker Material type – Sequence of activities performed on material Equipment type – Sequence of activities performed by equipment iii) Multiple Activity chart – Activities of more than one man or machine are recorded on a common time scale iv) Two handed Process chart – Activities performed by two hands of worker are recorded on a common time scale v) SIMO chart – Detailed version of two handed process chart (micromotion study) vi) Flow diagram – Shows the relative position of machines and equipments and marks the path followed by man and material

vii) String diagram – similar to flow diagram except that path is traced by a continuous string or thread viii) Cycle graph – To study the path of movement of operators hands; A small electric bulb is attached to hand and photograph is taken by a still camera ix) Chronocycle graph – Similar to cycle graph except that along with path it also shows direction and speed of movement. This is done by interrupting the light source so that path appears as a series of dots.

SIMO chart is Micromotion study whereas cycle graph and chronocycle graph are Memo Motion Study Memo Motion study involves time-lapse photography ie a still camera takes pictures of the activity at regular intervals (1 to 5 sec) unlike micromotion study which involves making a continuous motion film Memo motion study is used for activities which are not required to be examined in fine detail but are still too fast to be recorded accurately by human eye. Therbligs – are the fundamental hand motions which are performed over and again in any manual work, eg Search, find, select, hold, grasp, use, assemble, dissemble, inspect, release

-developed by Mr. Gilbreth (Therblig is his name spelled backward) -used in micromotion study Work Measurement Std. time for any job may be established by 3 methods:

Time Study (stop watch) Short cycle ; Repetitive jobs Work Sampling Long cycle ; Heterogeneous operations PMTS Short cycle ; Highly-repetitive jobs

Work sampling Time study Synthetic time

P.M.T.S. Analytical estimating Direct Indirect Work Measurement

Work Sampling In this a no. of observations are made over a period othat instant. The percent of observations recorded for a particular activity is a measure of the percentage of time during which that activity occurs.

Work Sampling is used for activities of very long duration which cannot be measured with stopwatch. Eg to find out actual working time of an operator in one shift.

It is based on Statistical theory of sampling – ie adequate random samples of observations spread over a period of time can construct an accurate picture of the actual situation of system.

No. of observations required for 95% confidence level and ±5% accuracy (ie we are sure that 95% of the time the average value will not be having error more than 5% of the true value.

N = 4p(100-p) (p = percent of occurance) --------------(A = Accuracy required) A2

StopWatch TimeStudy

Why do we break down the activity to be studied into elements?(why not measure time straightly) To provide a detailed work specification To separate value adding & non-value adding activities To select best method by comparing work elements of different methods

Stopwatch – one revolution = 1 minute (1 deciminute = 1/100th of minute)

Normal time = Observed time * rating factor Standard time = Normal time + allowances

Rating – Comparing the pace rate or performance of a worker against standard performance level to take into account different operators’ performance level

Rating techniquesSpeed- Worker’s speed/speed expected

However assigning a rating factor and allowances are largely subjective in nature and depends on personal judgment of timestudy engineer

Allowances- it is the additional time provided over and above normal time to take into account time for relaxation, attending personal needs   

Rest and personal allowances (to overcome fatigue incurred during working) Interference allowances (to take into account m/c stoppages etc) Special allowances (for activities which are generally not a part of work cycle)

In this we build up the total time for a job by summing up the times for different elements Particularly useful for operations which are still in the planning phase and have not yet started (helpful in planning and scheduling)   

Synthesis PMTS (Predetermined Motion Time System) Analytical estimating

Synthesis Element time values are taken from a catalogue of elements time built from timestudies done in the past PMTS also make use of previously collected data but it deals with basic human motions (or therbligs) of duration 0.1 seconds or less. Whereas in synthesis duration may be 3-4 seconds Analytical estimating is used when past time data is not available and estimator has to rely on his past experience.

PMTS     

For short cycle & highly repetitive jobs Uses video film (micromotion study) More accurate than stopwatch timestudies No rating factor required but allowances need to be added But can deal with only manual motions of the operation

Method Time Measurement Work Factor Systems

1 TMU = 0.0006 minutes (TMU = Time Measurement Unit) 1 wink = 0.0005 minutes (used in SIMO chart/micromotion study)

Analytical Estimating

For long and non-repetitive operations ; Least accurate

(Machine elements – calculated from information of feed, speed, depth of cut etc)

Comparison It is difficult to compare different work measurement techniques, as each technique has its own set of application

Work sampling is used for long cycles eg amount of time actually spent working by a worker in a shift

Time study is used for short repetitive cycles eg worker working on a assembly line

[[Bold]] textPMTS is used for very short cycles which require a very detail analysis (micromotion study)

Time study Work sampling Synthetic time P.M.T.S. Analytical

Time Required MAX MIN

Accuracy MAX MIN

TIME & MOTION STUDY : A NEW PARADIGM

In theory there is no difference between theory and practice, In practice there is …….

I realized it by myself when I undertook a project on time & motion study during my summer internship. On paper it looks very easy to do timestudy with a stopwatch. But when you actually do it you realize the practical difficulties associated with the traditional method. stung

That’s why I picked up the cause in my final year project and developed a software which automates the process of time & motion study.

Details about it can be seen at the following URL -:

http://in.geocities.com/time_motion_study http://www.professays.com/faq/

Please go through it; its worth a watch……

Multiple Activity Chart (Man-machine chart) for hole punching operation

Outline Process Chart

In records principle operations and inspection of the processes

Definition (as per BS 3138) A process chart giving an overall picture by recording in sequence only the main operations and inspections

Amount of Details It shows only two principal elements: (i) Operations, and

(ii) Inspection

Application Used in the preliminary investigation

When operation activities are subject to frequent changes or a more detailed analysis

Outline Process Chart for Repairing a Punctured Scooter

Some Conventions in Outline Process Chart

Activity 2 and inspection 1 occurs four times, but the number used in repeat line is always one less than the total as the first occasion is already plotted before the repeat break (Hence the (n-1) rule)

Symbols showing duplicate operation 2

Symbol showing dismantling and re-assembly

Email Based Homework Assignment Help in Questions on Multiple Activity Chart Transtutors is the best place to get answers to all your doubts regardingMultiple Activity Chart. You can submit your school, college or university level homework or assignment to us and we will make sure that you get the answers you need which are timely and also cost effective. Our tutors are available round the clock to help you out in any way with industrial management.

Live Online Tutor Help for Questions on Multiple Activity Chart Transtutors has a vast panel of experienced industrial management tutors who specialize inMultiple Activity Chart whocan explain the different concepts to you effectively. You can also interact directly with our industrial management tutors for a one to one session and get answers to all your problems in your school, college or university level industrial management. Our tutors will make sure that you achieve the highest grades for your industrial management assignments. We will make sure that you get the best help possible for exams such as the AP, AS, A level, GCSE, IGCSE, IB, Round Square etc. A Two-Handed Process Flow Chart individually shows the movement of each hand in a manual process. It is typically used when analyzing a manual assembly process, to help make it easier to perform.

Fig(Two-Handed Process Flow Chart)

Travel Chart (Also Called as Cross Chart)

It is a more detailed type of movement chart in which the recorded details are like:

(i) Pattern of movement,

(ii) Extent of movement or volume.

Definition (as per BS 3138) It is a tabular record for presenting quantitative data about the movement of workers, materials or equipment between any number of places over any given period of time.

Amount of Details Volumetric data during travel between work-area.

Application For studying layout problem in deciding how to minimize total flow (of material) in the plant or work-place.

Travel Chart

Multiple Activity Chart

Synonyms: activity analysis; worker and machine charts

Definition (as per BS 3138)

It is a chart on which the activities of more than one subject (like worker, machine or equipment) are each recorded on a common time-scale to show their relationship.

Amount of Details Limited to plot against a common scale (of time) for few types of activities like operation, idleness, delay, etc.How to construct

(i) Start with the preparation of flow process chart for elements like machine or operative involved in the process.

(ii) Group activities to be recorded into convenient elements for time-study.

(iii) Take sufficient observations of time-study for determining accurate elemental time.

(iv) draw in the form of bar-chart for each activity of the leading operative or machine. Take a common scale such as time for each activity.

(v) Use different colour codes for different sections within each bar.

(vi) calculate the amount of effective work per cycle in percentage of total time.

Application (i) For preliminary investigation to study the extent of accuracy of particular activities

(ii) Helps in balancing activities

(iii) In a situation of one operative running one or several operatives

(iv) In a situation of several operatives running one or several machines

(v) A team of operatives or a bank of machines

(i) Helps in exploring the possibilities of elimination, change in work sequence, combination and simplification of work elements.

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Live Online Tutor Help for Questions on Travel Chart Transtutors has a vast panel of experienced industrial management tutors who specialize intravel chart whocan explain the different concepts to you effectively. You can also interact directly with our industrial management tutors for a one to one session and get answers to all your problems in your school, college or university level industrial management. Our tutors will make sure that you achieve the highest grades for your industrial management assignments. We will make sure that you get the best help possible for exams such as the AP, AS, A level, GCSE, IGCSE, IB, Round Square etc.