1_Introduction to Work Measurement_Time Study

7/28/2019 1_Introduction to Work Measurement_Time Study

1/62


2/62

Introduction to

Work Measurement

This discusses the work measurement

techniques and the uses of each technique.

The techniques will help the analysts

establish standard times.


3/62

Work Measurement

Work measurementis the application of

techniques designed to establish the time for a

qualified worker to carry out a task at a definedrate of working(ILO, 1992).

The result of the work measurement is

standard time.


4/62

Purposes of Work Measurement

(1/2)

Work Measurement can be used in investigating,

reducing, and subsequently eliminating

ineffective time, that is the time during which no

effective work is being performed, whatever the

cause.

Work measurement can provide management

with a means of measuring the time taken in the

performance of an operation or series ofoperations in such a way that ineffective time is

shown up and can be separated from effective

time.


5/62

Purposes of Work Measurement (2/2)

Work measurement can be used to set standard

times for carrying out the work, so that, if any

ineffective time does creep in later, it will

immediately be shown up as an excess over the

standard time and will thus be brought to theattention of the management.

Work measurement reveals the management

itself and the behavior of the workers.


6/62

Work MeasurementTHE USE OF WORK MEASUREMENT:

In the process of setting standards it may be necessary to use

work measurement (1/3):

To compare the efficiency of alternative methods. Other

conditions being equal, the method which takes the least timewill be the best method.

To balance the work of members of teams, in association with

multiple activity charts, so that, as nearly as possible, each

member has a task taking an equal time to perform.

To determine, in association with worker and machine multiple

activity charts, the number of machines an operative can run.

The time standards, once set, may be used.


7/62




To provide the basis for production planning and control forthe choice of a better layout and for the process planning, and

for establishing just-in-time inventory control systems.

To provide information that can enable estimates to be made

for tenders, selling prices and delivery dates.


8/62




To set standards of machine utilization and labor performancewhich can be used for any of the above purposes and as a

basis for incentive schemes.

To provide information for labor-cost control and to enable

standard costs to be fixed and maintained.


9/62

Work Measurement

The following ways can be used to measure and

establish standard times.

Time Study Work Sampling

Standard Data

The Fractioned Professional Estimate

Predetermined Standard Times


10/62

TIME STUDY

Time study is the most versatile and most widely used

technique for measuring work in industry.

TIME STUDY is used to determine the time required by aqualified and well-trained person working at a normal

pace to do a specified task.

It is used to measure work.


11/62

Uses of Time Study

- It originally had its greatest application in connection with wage

incentives;

Used for purposes including:

1. Determining schedules and planning work.

2. Determining standard costs as an aid in preparing budgets.

3. Estimating the cost of a product before manufacturing it; Such

information is of value in preparing bids and in determiningselling price.


12/62

Uses of Time Study

- It originally had its greatest application in connection with wage

incentives;

Used for purposes including:

4. Determining machine effectiveness, the number of machineswhich one person can operate, and as an aid in balancing

assembly lines and work done in conveyor.

5. Determining time standards to be used as basis for the

payment of a wage incentive to direct labor and indirect labor.

6. Determining time standards to be used as a basis for labor

cost control.


13/62

Time Study Equipment

The equipment needed for time study consists of a timingdevice and an observation board.

Decimal Stop Watches and Electronic Timers

The stopwatch and theelectronic timer are the

most widely used timing

devices for a time study.


14/62

Decimal Minute Watch

-It has 100 divisions on its

face, and each division is

equal to 0.01 minute, that

is a complete sweep of the

long hand requires one

minute.The small dial on the watch

face has 30 divisions, each

of which is equal to one

minute. Therefore, for

every full revolution of the

sweep hand, the small

hand moves one division,

or one minute.


15/62

Electronic Stopwatch

- It provide resolution to0.001 second and an

accuracy of 0.002

percent. They weigh

about 4 ounces and areabout 4x2x1 inches in

size. They permit timing

any number of individual

elements, while also

counting the total elapsed

time.


16/62


Video CamerasIt is ideal for recording operators methods

and elapsed time. The analysts can record

exact details of the method used and can

then assign normal time values, anywayrecorded films can be reviewed at the

analysts convenience.

Standards can be established by projecting

the film at the same speed that the pictureswere taken and then performance rating the

operator. Because of all the facts are there,

observing the videotape is a fair and

accurate way to rate performance.


17/62


Observation boardA lightweight board, slightly larger than the observation

sheet, is used to hold the paper and the stopwatch.


18/62

Time study requires direct

observation, thus the time study

board should be brought by the

observer to the operation

conveniently.

It should be light, easy to handle

so as not to harm the hand, butstrong to provide a suitable

backing for the time study form.

The board should be slightly largerthan the study forms but must

have a shape that allow the

observer for comfortable fit and

ease of writing while it is being

held.


19/62


Observation SheetA printed form with spaces provided for recording information

about the operator being studied.

This information usually includes a detailed description of the

operation, the name of the operator, the name of observer,the time, date, and place of study, also the working

condition.

The form also provide spaces for recording stop-watch

readings for each element of the operation, performance

ratings of the operator, and computations. Space may beprovided for a sketch of the workplace, a drawing of the

part, and specifications of the materials, jigs, gauges, and

tools.


20/62


21/62

Request for a Time Study

It is not made unless an authorized person requests it.

(Usually it is the supervisor who requests that a study be

made, but the plant manager, chief engineer, production

control supervisor, cost accountant, or other member of the

organization may make such request.)

If a time standard is to be established on a new job for the

wage incentive purposes, it is to be made certain that the

operation is running satisfactorily before requesting the

study. The supervisor should also see that the operatorshave thoroughly learned the job and that they are following

the prescribed method.


22/62

Is the Job ready for Time Study?

The time standard established for a job will not be correct

if the method for doing the job has changed, if the

materials do not meet the specifications, if the machine

speed has changed, or if other conditions of work aredifferent from those that were present when the time

study was originally made.


23/62

Is the Job ready for Time Study?

The time study analyst should ask the following questions:

Can the speed or feed of the machine be increased without

affecting optimum tool life or without affecting the quality of

the product?

Can changes in the tooling be made to reduce the cycle

time?

Can materials be moved closer to the work area to reduce

handling time?

Is the equipment operating correctly, and is a qualityproduct being produced?

Is the operation being performed safely?


24/62

Making the Time Study

Steps in Conducting a Time Study:

1. Select the job to be studied.

2. Obtain and record all the information available about

the job, the operator, and the working conditions.

3. Record the complete description of the method,

breaking down the operation into elements.

4. Examine the detailed breakdown to ensure that the

most effective method and motions are being used, and

determine the number of observations (sample size) for

every element.


25/62


Steps in Conducting a Time Study:

5. Measure and record the time taken by the operator to

perform each element for the operation.

6. Rate the operators speed relative to the observersconcept of standard performance.

7. Extend the observed times to basic times.

8. Determine the allowances to be made over and above

the basic time for the operation.

9. Determine the standard time for the operation.


26/62


The analyst should check the method used by the

operative before proceeding to the study. If the intention of

the analyst in conducting a time study is to establish time

standards, an investigation on the productivity of the

method used should be done first. This is to ensure that

the standard time conforms to standard performance.


27/62


Work Cycle - sequence of elements which are required to

perform a job or yield a unit of production. The sequence

may sometimes include occasional elements (ILO, 1992).

Element - a distinct part of a specified job selected for

convenience of observation, measurement and analysis.


28/62


Recording Information

All information requested in the heading of the observation

sheet should be carefully and clearly recorded.

- time studies hastily and incompletely made are of little value.

Necessary information concerning operation, part, material,

customer, order number, lot size, etc. can be obtained from

the route sheet, BOM, or the drawing of the part.

A sketch of the workplace should also be included showing

the working position of the operator and the location of

tools, fixtures, and materials.

Accurate record should be made.


29/62


Dividing the operation into Elements andrecording description of the method

If a previous record or manual on a certain procedure is not

available, the time study analyst must observe carefully

the operations and the motions that are being performed bythe worker in accomplishing a job. He then must record all

this information to carefully break down the operation into

measurable elements.


30/62


Reasons for Element Breakdown (1/2):1. One of the best ways to describe an operation is to break it

down into definite and measurable elements and describe

each of these separately. Elements that occur regularly are

listed first, and then all other elements that are a necessarypart of the job is described.*

2. Standard time values may be determined for the elements

of the job. Such element time standards or standard data

make it possible to determine the total standard time for anoperation.


31/62


Reasons for Element Breakdown (2/2):

3. A time study may show that excessive time is being taken to

perform certain elements of the job or that too little time is

being spent on other elements.

4. An operator may not work at the same tempo throughout

the cycle. A time study permits separate performance

ratings to be applied on each element of the job.


32/62


Types of ElementsEight types of elements are distinguished to aid the

analyst in breaking down the job:

1.Repetitive

2.Occasional

3.Constant

4.Variable

5.Manual

6.Machine7.Governing

8.Foreign


33/62


Types of Elements (1/3): Repetit ive elemen t- is an element which occurs in

every work cycle of an operation.

Occasional element- is an element which does not

occur in every work cycle of an operation but which mayoccur at a regular or irregular interval/s.

Cons tant element- is an element for which the basic

time remains constant whenever it is performed.

Constant elements may be repetitive or occasional, similarly,

repetitive elements may be variable or constant.


34/62


Types of Elements (2/3): Variable element- is an element for which the basic

time varies in relation to some characteristics of the

product, equipment or process, e.g. dimensions, weight,

quality, etc.

Manual element - is an element performed by the

worker.

Mach ine element -is an element performedautomatically by any process, physical, chemical,

otherwise that, once started, cannot be influenced by a

worker except to terminate it prematurely.


35/62


Types of Elements (3/3): Governing element- is an element occupying a longer

time within a work cycle than that of any other element

which is being performed concurrently.

Foreign element - is an element observed which does

not form a part of the operation(s) being studied.


36/62


Rules in Breaking down operation intoelements:

Elements should be easily identifiable, with definite

beginnings and endings, so that, once established, they

can be repeatedly recognized.

Elements should be as short as can be conveniently

timed by a trained observer.

As far as possible, element, particularly the manual

ones, should be chosen so that they represent naturallyunified and recognizably distinct segments of the

operation.


37/62


Rules in Breaking down operation intoelements:

Manual elements should be separated from machine

elements.

Constant elements should be separated from variable

elements.

Elements which do not occur in every cycle should be

timed separately from those that do.

The length of each element may depend on the type of

operation. The tools and equipment to be used would

vary on the type of operation.


38/62


Taking and Recording the Data

Continuous Timing (Split timing)

- the watch is started at the beginning of the study

and permits it to run until the end of the study.

Repetitive Timing (Lap Timing)

- the hands of the watch are snapped back to zero

at the end of each element.

Accumulative Timing

- permits the direct reading of the time for each

element by using two stopwatches.


39/62


Recording the stopwatch readings

It may be difficult for the observer to do several things

in a quick succession, namely: observe the

operator, read the watch, and record the data on the

observation sheet; but it is possible after somepractice.

The general policy of carefully timing every part of the

operation should be a requirement.


40/62


Recording the stopwatch readings

- Elements such as: change tools, blow chips out of

jig, move finished parts, lubricate die should be

considered and timed.

- Foreign elements may or may not be included in the

time standard.


41/62


Number of Cycles to be Timed

The time required to perform the elements of an operation

may be expected to vary slightly from cycle to cycle.

Variations in time may result from things such as

difference in the exact position of the parts and toolsused by the operator; or from possible differences in

the end point of a watch reading.

Time study is a sampling process; the greater the number

of cycles timed, the more nearly the results will be

representative of the activity being measured.

F l f D t i i


42/62

Formula for Determining

Number of Observations

Number of Cycles to be TimedInitial observations should be made to determine the number of

observations needed to establish a standard time. The

initial observations will determine the variability of the time

for each element. Statistical methods can help an analystdetermine the appropriate number observations using the

following formula with 95 percent confidence interval:

Where N= required number of observations

N= number of initial observation taken

X= individual observation times

N= 40 N(X2)(X)2 )

(X)[

2

]


43/62

Example:

The ten initial observations to an operator working on an

element insert bolt in the rear part, lock using washer and

nut revealed:

Observation No. 1 2 3 4 5 6 7 8 9 10Observation Time

(minutes) 10 12 14 11 12 14 12 12 10 13

The number of observations at required is computed as :

X = 120; X2 = 1,458


44/62

Example:

Using the formu la:

[N= 40 N(X2)(X)2 )(X)2]

[N= 40 10 (1458) (120)21202]

N = 20 observations


45/62


Rating

As the time study analyst records the data, he also

evaluates the operators speed in relation to his opinion

of normal speed for such an operation.

Rating is the assessment of the workers rate of workingrelative to the observers concept of rate corresponding

to standard performance (ILO, 1992). Standard

performance is the rate of output which qualified workers

will naturally achieve without over-exertion as anaverage over the working day or shift, provided that they

know and adhere to the specified method and provided

that they are motivated to apply themselves to their

work.


46/62


Rating

A common method is for the analyst to determine the rating

factor or the operation as a whole.

Another method is to determine a rating factor for each

element of the operation (possible when the time for

each elements are fairly long).


47/62


Rating

The rating can be used as a factor by which the observed

time can be multiplied to give the basic time, which is the

time it would the motivated, qualified worker to carry out

the element at standard rating. A qualified worker is onewho has acquired the skill, knowledge and other

attributes to carry out the work in hand to satisfactory

standards of quantity, quality and safety.

The common scales of rating used are the 60-80, 75-100,and 100-133 scales, and the British Standard scale.

Comparable


48/62

SCALES DescriptionComparable

walking speed

60-80 75-100 100-1330-100

Standard(mi/h) (km/h)

0 0 0 0 No activity

40 50 67 50 Very slow; clumsy, fumbling movements;operative appears half sleep, with no

interest in the job

2 3.2

60 75 100 75

Steady, deliberate, unhurried performance,

as of a worker not on piece work but under

proper supervision; looks slow, but time is

not being intentionally wasted while under

observation

3 4.8

80 100 133

100

(standard

rating)

Brisk, business-like performance, as of an

average qualified worker on piece work;

necessary standard of quality and accuracy

achieved with confidence

4 6.4

100 125 167 125

Very fast; operative exhibits a high degree

of assurance, dexterity, and coordination

of movement, well above that of an

average trained worker

5 8

120 150 200 150

Exceptionally fast; requires intense effort

and concentration, and is unlikely to be

kept up for long periods; a virtuoso

performance achieved only by a few

outstanding workers.

6 9.6


49/62


FOUR Factors of Rating

1. Skill

2. Consistency

3. Working Conditions

4. Effort (most important)


50/62

Factors of Rating

1. Skill

The effect of skill is minimized by timing only people who

are skilled. Operators must be fully trained in their work

classification before being time-studied.

2. Working conditionWorking conditions can affect the performance of an

operator. If employees are asked to work in hot, cold,

dusty, dirty, noisy environments, their performance will

suffer. If operators are required to lift heavy materials inthe performance of their duties, 25% more time can be

added to the time standard as an allowance. Working

conditions are not part of modern rating.


51/62

Factors of Rating

3. Consistency

Consistency is the greatest indication of skill. The operator is

consistent when he or she runs the elements of the job in

the same time, cycle after cycle. Consistency is used to

determine the number of cycles. A consistent operator

needs to run only few parts before the cycle time is knownwith accuracy. The skill of the operator should be evident to

the time study technician, and the technicians rating of the

operator should be high.

When inconsistency is present, the technologist must takemany more cycles to be acceptably accurate in the time

study. This inconsistency tends to affect the technologists

attitude and rating of the operator in a negative way, and

the best thing to do is find someone else to study.


52/62

Factors of Rating

4. Effort

Effort is the most important factor in rating. Effort is the

operators speed and/or tempo and is measured based on the

normal operator working at 100%. A 100% performance rating

is defined as:

Walking 264 feet in 1.00 minute or 3 miles per hour,

Assembling thirty 3/8 x 2 pins into a pinboard in 0.435

minute.

Effort can be seen easily in walking. Walking at speeds less

than 100% is uncomfortable for most people, and walking at120% requires a sense of urgency that indicates increased

effort.


53/62


Allowances

The normal time or the basic does not include unavoidable

delays, which may not even be observed and other

legitimate lost time because watch readings of any time

study are taken over a relatively short time. Consequently,

analysts must make some adjustments or allowances to

compensate for such losses.


54/62


Main types of Allowances

Fatigue allowances

- It provides time for the workers to recover from fatigue

incurred as a result of the job or work environment, and theseare subdivided into constant and variable fatigue allowances.

Special allowances

- It includes many different factors related to the process,equipment, and materials and are termed unavoidable

delays, avoidable delays, extra, and policy allowances.


55/62

Types of Fatigue Allowances

Constant Allowances Personal Needs

It includes those stoppages in work necessary for

maintaining the general well-being of the employee

such as trips to the drinking fountain and the

restroom. If the general working conditions and class

of work of the employee is good, only a small

percentage of the time is needed but for employees

whose working conditions have high temperature orextreme cold, their time may be influenced by

personal delays.


56/62


Constant Allowances Basic Fatigue

The basic fatigue allowance is a constant to account for

the energy expended to carry out the work and to alleviatemonotony. A value of 4 percent of normal time is

considered adequate for an operator who is doing light

work, while seated, under good working conditions, with

no special demands on the sensory or motor systems

(ILO, 1957). Between the 5 percent personal needsallowance and the 4 percent basic fatigue allowance, most

operators are given an initial 9 percent constant

allowance, to which other allowances may be added, if

necessary.


57/62


Constant Allowances Variable Fatigue Allowance

Fatigue is not homogeneous in any respect. It ranges from

strictly physical to purely psychological or combinations of thetwo. The result is a decrease in the will to work. The major

factors that affect fatigue include working conditions,

especially noise, heat, and humidity; the nature of the work,

such as posture, muscular exertion, and tediousness; and the

general health of the worker. Although heavy manual work,and thus muscular fatigue is diminishing in industry, due to

the mechanization, other fatigue components, such as mental

stress and tediousness, may be increasing. Because not all

fatigue can be eliminated, proper allowance must be made for

the working conditions and repetitiveness of the work.


58/62

Types of Special Allowances

Unavoidable Delays

This class of delay applies to effort elements and includes

interruptions from the supervisor, dispatcher, time study

analyst, and others; material irregularities; difficulty in

maintaining tolerances and specifications; andinterference delays where multiple machine

assignments are made.

Unavoidable delays are frequently a result of material

irregularities.


59/62


Avoidable Delays

It is not customary to provide any allowance for

avoidable delays, such as visits with other operators

for social reasons, uncalled-for work stoppages, and

idleness other than rest to overcome fatigue. Whileoperators may take these delays at the expense of

output, no allowance for these breaks of work is

provided in the development of the standard.


60/62


Extra Allowances

One extra allowance frequently used, especially in the

steel industry, is a percentage added to a portion or all of the

cycle time to account for the operator observing the process to

maintain efficient progress of the operation. This allowance isfrequently referred to as attention time allowance and may

cover such situations as an inspector observing tin plate

coming off the line, first helper observing the conditions of a

molten bath or receiving instructions from the melter, or a

crane operator receiving directions from the crane hooker.Without this extra allowance, such operators would find it

impossible to make the same earning as fellow employees.


61/62


Policy Allowances

It is used to provide a satisfactory level of earnings for a

specified level of performance under exceptional

circumstances. Such allowances could cover new

employees, workers on light duty, and others. Theseare typically decided by management, perhaps with

union negotiations.


62/62


Applying AllowanceStandard time is the total time in which a job should be

completed at a standard performance. Allowances are

added to the basic times as follows:

Standard time = Basic Time + (Basic Time X Allowance, in percent)= Basic time X (1 + Allowance, in percent)

An alternative approach is to formulate the allowances as a fraction of

the total workday, since the actual production time might not be

known. In that case, the expression for standard time is:

Basic Time

---------------------------------------

(1 allowance, in percent)Standard time =

1_Introduction to Work Measurement_Time Study

Documents

Transcript of 1_Introduction to Work Measurement_Time Study