1. INSY 3021 Auburn University Spring 2007
Work Sampling
INSY 3021
Auburn University
Spring 2007

2. Work Sampling
A technique that discovers the proportions of total time that various activities contribute to the job by taking a relatively large # of observations at random intervals
Used to determine: production standards, machine and personnel utilization, and job allowances. Typically faster and cheaper than other techniques

3. Advantages
Well suited for high cycle time and low repetition rate jobs & service industry
Does not require the analyst to continually observe the job
Reduced clerical time
A smaller # of hours are required to collect the data
Operator not subjected to long periods of observations

4. Advantages (con’t)
Single analyst can study a small crew (or # of subjects); GTT (Maynard Handbook)
Cost of the study may be cheaper (up to a certain # of samples)
Conducted over a long period of time (tends to be more objective)
Study can be postponed if something more urgent arises (no change in study criteria)

5. Disadvantages Will not produce as good a standard as direct time study
Cost maybe higher than suspected if sampling rates are frequent
Subjects need to be located close together to eliminate travel
Doesn’t provide the detailed data (C/I ideas) that direct study does
Theory of why it works is confusing for some people

6. Little bit of theory Based on an event being present or not.
Probability of x occurrences of an event in n observations: (p + q)n = 1
Expand IAW binomial theorem, with the 1st term giving the probability of x=0, the 2nd term x=1, etc…
This distribution of probabilities is known as the binomial distribution, with the Mean = np, and Variance = npq.
As n becomes large, the binomial distribution approaches the normal distribution
We’ll return to this later…

7. Sample Size
There are many sources of tabulated data for determining the # of samples required at various confidence levels and accuracy’s.
Formula for calculation purposes simplifies to: n = Z2(1-P)/(P)(A2)

9. Study Plans (Protocol)
Start with preliminary estimate of the variable. This can be historical data, conducting pilot study, or an educated guess (least desirable)
Determine the desired accuracy of the results
What level of confidence do you desire
Estimate the # of observations
Develop a sampling schedule
Design the data collection form

10. Determining Randomness
Random number tables (text pg. 697)
Random number generators
C++ Program
Websites
Random Reminder

11. Work Sampling Form (Instrument)
Forms should be custom designed to accommodate the specific data of interest to your study. Make the spaces large enough to easily record the data. Provide summary and calculations spaces right on the form.
Commercial software available for this application

13. Technique
Locate yourself at the same place each time prior to observing the operation
Try to intentionally distract yourself from the variable of observation as you approach the site (think safety)
Limit your time at the site to that actually needed for the observation

14. Technique (con’t)
Try to record only the minimum data that you will need to successfully reconstruct the observation
Verify any discrepancy with the supervisor or foreman
Make notes on the form after the operator can no longer see you
Keep a pleasant attitude

15. Computerized Work Sampling
Computer and PDA programs
Quetech Ltd, TimerPalm, UMT-Palm
Advantages
IE time increased by a reduction in clerical time, results realized faster
More professional appearing report
$ of performing studies is cheaper
Improved accuracy
Reduced errors by analysts
Greater use made of work sampling, because it is less painful

16. Work Sampling Studies Title
Determining staffing requirements in institutional pharmacy
Objective
To determine if improvements can be made to workload & staffing patterns of a satellite pharmacy; determine the percentage of an employee’s day which was devoted to specific activities
Sample
1 pharmacy
Type of sampling
Predetermined times
Length of study
3 weeks (day, evening, & night shifts)
Data Collection
Direct observation
# Observations
2400 (300 per shift)

17. Work Sampling Studies # Observations 1,451 Title
Task analysis of a pharmacist’s activities in a 45-bed rural hospital with comprehensive pharmaceutical services
Objective
Determine how a pharmacist’s time was used; calculate the portion of the work day spent in clinical pharmacy activities; compare allocation of time in this service with that of pharmacists in a small hospital with product-oriented systems; investigate potential usefulness of supportive personnel
Sample
1 pharmacy
Type of sampling
Fixed intervals – 5 minute intervals
Length of study
18 days selected randomly work days (stratified to insure equal representation of each day) over a 6-month period
Data collection
Direct observation - 5 trained observers
# Observations
1,451

18. Work Sampling Studies Title
What Are the Functions of a Practicing Pharmacist?
Objective
Detailed examination of what pharmacy operators do with their time
Sample
20 pharmacies (stratified into 4 levels based on prescription volume); 93 pharmacists
Type of sampling
Fixed intervals – 3 minute intervals; stratified based on prescription volume
Data collection
Direct observation – 1 observer
Length of study
36 hours (stratified to insure each day of week and hour of day were adequately represented)
# Observations
14,400

19. Work Sampling Studies Title
Work activities of pharmacy teams with drug distribution and clinical responsibilities
Objective
Evaluate pharmacists’ and technicians’ use of time for patient care.
Sample
7 pharmacy teams (3-9 pharmacists & 1-4 technicians per team)
Type of sampling
Random time interval (8 observations / hr / shift)
Data collection
Self reporting
Length of study
5 months
# Observations
11,485 pharmacist observations; 7,626 technician observations

20. Work Sampling Studies Title
Work Sampling: As a Win/Win Management Tool
Objective
Detailed examination of what pharmacy operators do with their time –seeking ways to improve the efficiency of the operation.
Sample
Type of Sampling
Random intervals (20-25 observations/shift)
Data Collection
Self reporting
Length of study
3 months
# Observations
2518 samples

21. Work Sampling Studies Title
Work Sampling: The Application of an Industrial Research Technique to School Library Media Centers
Objective
Apply work sampling in a school library media center setting
Sample
1 media center; 2 media specialists
Type of sampling
Random time interval (4 observations per hour)
Data collection
Self reporting
Length of study
20 days
# Observations
400

22. Work Sampling Studies Title
Work Sampling: Assessing nursing efficiency
Objective
Determine how nurses utilize their time
Sample
16 RN’s; CNA’s; 3-4 secretaries
Type of sampling
Predetermined times (20 minutes each shift)
Data collection
Direct observation
Length of study
24 hours (4 day shifts, 4 evening shifts, 2 night shifts on weekdays and weekends)
# Observations
2,835

23. Summary “Sell” the work sampling method before using it
Use as large of a sample size as is practical
Take individual observations at random times, balance the study if necessary
Take the observations over two weeks or more

24. Questions & Comments