Case Study: Work Sampling for Sewing Floor


The objective was to conduct work sampling to standardize sewing allowance rate for the operators.


  • The study was conducted for one line.
  • Observation was taken over whole day. 
  • Total 32 sewing operators and 8 helpers were selected for the study. 
  • The observations were performed by watching the operations and judging a particular operation at a given time. Observation data were filled in the given format (work study sampling). 
  • After observing operators for one cycle of forty readings same procedures were repeated. 
  • Times of observations were selected randomly. 
  • The observations were then calculated under each element as the frequencies
  • Allowance rate was calculated for each element in percentage. 
  • Total 400 reading were taken. 
Details of the collected data have been shown in the following table.

Benefits of Work Sampling:

  • Yardstick for control level.
  • By comparing results of analytically investigations with the general ratio of main operations, associated operations and allowance. The control level of the company can be roughly understand. The standards results may be used as a yard stick. 
  • Work sampling is done to find out allowance rate which is useful in setting SAM 
Results of work sampling:
Operation allowance rate:
            Main Operation = (160/400)*100 =40%
            Associated Operation = (133/400) X100 = 33.25%

Results:Allowance Rate = 26.75
Major loss of production time is due to –
Waiting = 9.75%
Trouble = 2.5%