sentences:  Activity Sampling
  
  Activity sampling is a technique in which a large number of instantaneous observations are made over a period of time of a group of machines, processes or workers.Each observation records what is happening at that instant and the percentage of observations recorded for a particular activity or delay is a measure of the percentage of time during which the activity or delay occurs.The advantages of this method are that
  
  It is capable of measuring many activities that are impractical or too costly to be measured by time study.