Occupancy and utilization are two call center terms that are used interchangeably in the industry. Both reveal the percent of time call center agents are on calls or in wrap-up (basically, doing call-related work).
Shrinkage is a measure of how much time is lost to things like vacation, breaks, lunch, holidays, sick time, and training. So you calculate it by first defining what you need to include, and then defining how much time is needed for these things. It is often expressed as a percentage, but can also be a factor applied to the number of staff needed active on phones to reflect the number you need to schedule (e.g., 1.3)
This was first published in November 2006