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

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

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

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)

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

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…

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)

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

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

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

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

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

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

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)

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

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

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

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

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

Work Sampling Studies Title Work Sampling: Assessing nursing efficiency Objective Determine how nurses utilize their time Sample 16 RN’s; 10-12 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

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

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