WORKSAMPLING

BY: GROUP 5AGACITA, ANGELICA

PANES, ISABEL FRUILENEMABASA, LANMARKANDALES, NILO IAN

Theoretical Background

The results of work sampling are effective for

determining machine and personnel utilization,

allowances applicable to the job and production

standards. Although, the same information can be

obtained by time study procedures, work sampling

frequently provides the same information faster and at

considerably less cost. (Niebels, 2007)

Stated by Niebel (2007)

The accuracy of data determined by work sampling depends on the

number of observations and the period over which the random

observations are taken.

The analyst should design an observation form to record the data to

be gathered during the work sampling study.

A standard form is usually not acceptable, since each work

sampling study is unique from the standpoint of the total

observations needed, the random times that observations are

made, and the information being sought.

In approaching the work area, the analyst must not

anticipate the expected recording.

(Niebel,2007)

If the operator to be studied is idle, the analyst must

also determine the reason for idleness and mark

this on the form (Niebel,2007)

Individual factors that affect performance: gender,

age, handedness, fitness and trainings (Miller

& Freivalds, 1987).

The control chart techniques used in statistical quality

control work can readily be applied to work sampling studies

to identify problem areas and be used to show the

progressive improvement of work areas.

(Niebel,2007)

The control chart, according to Deming (1988) is a means

of visualizing the variations that occur in the central

tendency and dispersion of a set of observations. It also

made use of a control limits that evaluate the

variations in quality from subgroup to subgroup.

Natural variation is the result of chance causes that

requires management intervention to achieve quality

improvement.

Unnatural variation is the result of assignable causes

requires corrective action by people close to the process such as

operators, clerks and any other workers

Assignable causes these can be readily identified and

predictable.

Chance causes these are random causes that are

inevitable, difficult to detect and identify.

PLOTTED POINT ISOutside control

limitsInside

control limits

Assignable Cause Present

OK Type II Error

Chance Cause Present

Type I Error OK

The control chart techniques used in statistical quality

control work can readily be applied to work sampling

studies to identify problem areas and be used to

show the progressive improvement of work

areas. (Niebel,2007)

The control chart, according to Deming (1988) is a

means of visualizing the variations that occur in

the central tendency and dispersion of a set of

observations. It also made use of a control limits

that evaluate the variations in quality from

subgroup to subgroup.

It is very important to take note of the

subgroup size.

As it increases, the control limits

become closer to the central

value, which makes the control chart

more sensitive to small variations in the

process average (Deming, 1988).

The service sector provides a special challenge to the accurate

measurement of productivity and productivity improvement. It is

difficult to improve because of the following factors: (Heizer and

Render, 2011)

Labor intensive

Frequently focused on unique individual attributes or desire

Often an intellectual task performed by professionals

Often difficult to mechanize and automate

Often difficult to evaluate for quality

To create a customer value in an efficient and sustainable way is an

idea of a competitive advantage. (Heizer and Render,2011)

The proponents made a preliminary work sampling of 30

observations in which the result of idle percentage was used

for another work sampling activity. The new number of

observations was obtained through the used of nomogram.

The proponents also made thorough research in constructing

a work sampling form and the process of work sampling

method.

Quantitative approach is being used in gathering and

analyzing the data. Only one person is being considered as

the subject of the study. The control chart was constructed

as to the details of per random times and per day

performance. In which, the out-of-control conditions gathered

were the bases for generating recommendations for

improvement.

1.How economical is the use of work sampling in determining the

following:

1.1 Working time

1.2 Idle time

1.3 Standard time

2. What are the problems or causes for the non – productive occurences

of the worker?

3. What are the possible recommendations that will improve the

productive occurrence of the worker?

This study will deal accordingly to answer the following questions:

PRESENTATION,ANALYSIS

AND INTERPRETATION

OF DATA

La-Fortuna Bakery, Inc.

• Name of the company

Carmen Sy

• Owner

Marfe Ancit

• Cashier/ all-around• 200 per day –wage

12,000php – 15,000php

• Estimated sales per day on regular basis

Layout of Workplace

Information Data for 6 Days

Total Time Expended by Operator

(Working time and Idle time)282 min

Working time in percent 58%

Total Number of Times Working 3600 times (6 days)

Idle time in percent 42%

Average Performance index 37.1%

Total Allowances 15%

Standard time

(Total time in min.)x(Working time in%)x(Performance Index in %)

Total number of times working

Allowancex

=

(282 x 0.58 x 3.71) ( 100 )

3600 (100 – 15)

0.20 min = 12 sec.

x=

=

Control limits p = p +3 √p(1-p) / n

N = 282 observations

n = total number of obs. = 282= 47number of days studied 6

p = No. of “idle” obs.= 118= 0.42total no. of obs. 282

CL for p = 0.42+3√(0.42 x 0.58) / 47

= 0.42 +0.22

UCL = 0.64

LCL = 0.20

Date of StudyTotal Number of

Obs.Number of Obs.

“Idle”% of Day

“Idle”

March 8 47 17 0.36 = 36%

March 9 47 22 0.47 = 47%

March 12 47 24 0.51 = 51%

March 13 47 16.

0.34 = 34%

March 14 47 20 0.43 = 43%

March 15 47 16 0.34 = 34%

0.64

0.52

0.42

0.32

0.20

8-Mar 9-Mar 12-Mar 13-Mar 14-Mar 15-Mar

pe

rce

nt

occ

ure

nce

Obs. No %non-prod. Obs. No. %non-prod. Obs. %non-prod.

1 17% 17 33% 33 33%2 17% 18 17% 34 17%3 17% 19 0% 35 33%4 17% 20 17% 36 33%5 17% 21 50% 37 33%6 17% 22 50% 38 50%7 17% 23 67% 39 33%8 50% 24 33% 40 100%9 83% 25 67% 41 83%

10 67% 26 50% 42 50%11 67% 27 17% 43 17%12 50% 28 33% 44 67%13 67% 29 50% 45 33%14 50% 30 100% 46 33%15 50% 31 67% 47 33%16 33% 32 33%

1.041.021.000.980.960.940.920.900.880.860.840.820.800.780.760.740.720.700.680.66

UCL 0.640.620.600.580.560.540.520.500.480.460.44

CL p 0.420.400.380.360.340.320.300.280.260.240.22

LCL 0.200.180.160.140.120.100.080.060.040.020.00

1 2 3 4 5 6 7 8 9 10

11

12

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15

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20

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24

25

26

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34

35

36

37

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42

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44

45

46

47

Perc

eta

ge

occure

nce

Observation Nos.

arrange

utensils

prepare

food

reco

rd ca

sh

count c

ash

Get;give

change

serve

food

clean are

a

wash dish

es0

5

10

15

20

25

30

35

40

45

50

Productive Occurrence

Occurrence

talk on phonelate

read ta

bloid

talk to co

-work

erswait

went home

sleep

take breakfast

texting

0

5

10

15

20

25

30

35

40

45

Non-Productive Occurrence

Occurrence

Working time and Idle time almost got a closer

result with 58% and 42% respectively.

Based from the types of out-of-control condition:

Trend or steady change in level --worker’s

performance is affected due to boredom and

inattention

Change or jump in level --there was an

unintentional change or minor failure made by the

worker such as being late and going home

(emergency cases). When it comes to service, the

co-worker is still attending the customer’s needs

or questions, and the worker (subject) would have

to wait.

Recurring Cycle – idleness take most between 8 am – 10:30

am and 3pm downwards. Working time takes most when it’s

mid-afternoon or the students are taking their lunch. Seasonal

effects or peak hours cannot be avoided and so, this affect the

condition of the worker’s performance.

Two populations – there is a large differences in the test

method or the random times being used. There are times when

the observation took place (1 min.) after the previous

observation, and the next observation will be done after 5

minutes or more. This affects the condition in such a way that

the result becomes bias.

Mistakes – this can be very embarrassing but there could

be a mistake in recording the data. In a case, where the

analyst have to assign other students to take records of

the data, yet that student doesn’t have a background of

work sampling and is careless with the random times, or

anticipate the recording of data.

The points outside the control limits showed that there

were chance causes present, such as going home for an

emergency and the peak hour of students for taking a

dinner or meal.

Natural Variation – the management has to facilitate the

performance of the worker when it comes to being late

Assignable cause – although the plotted points where

located inside the control limits there are still unnatural

variation that is to be considered, such as the service or

product that they offer. Most of their products (foods) are

identical with the other food shop in the canteen, the

management then, has to offer a new product.

Work sampling can provide information about the productive and

non – productive occurrence of the worker. However, it does not

provide a complete information about the method used by the

worker.

The behavior of the worker could also affect the data recorded

especially when the observations are made too obvious of the

worker and there is a shifting of performance.

Work sampling tends to average and generalize the results. The

variations of the results then will only lead to an inappropriate analyzation

of the problems.

The control chart helps determine the percentage occurrence of the non-

productive work per random times given. However, when it is measured

per day, there has to be a sample size per random times or subgroup.

That resulted to a generalization of the work for a single subject only, not

applicable for other workers present in the workplace.

The following recommendations are to be implemented: set – up the determined standard timeProduce a new product or menu to improve marketing serviceFacilitate the performance and behavior of the worker when it comes to being lateIncrease the wage payment from 200 php to 305php in accordance to the labor code, to satisfy the workers performance and job security.

Groover, M. (2007).Work Systems and the Methods, Measurement, and Management of Work. Pearson Education, Inc. New Jersey

Denton, K. (1982). Safety Management, Improving Performance. Mc-Graw Hill Book Company. New York

Deming, E. (1988). Quality Control Handbook. Mc-Graw Hill Book Company. New York

Freivalds, A. and Niebel, B. (2009). Niebel’s Methods, Standards, and Work Design.New York: Mc-Graw Hill Companies, Inc.

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