What's shrinkage?
Shrinkage is the time (or percentage of time) agents are not productive due to breaks, meetings, training, vacation, illness, absenteeism, etc. Most of these events can be build into the schedule, however there is one aspect of shrinkage that cannot be really planned for and it is related to adherence. Adherence is a measurement of the time agents are scheduled to work compared to the time they actually work. If agents leave early, start later or take longer breaks than specified in their schedule, it causes shrinkage that has an immediate impact on service levels and other call center metrics due to under-staffing.

How to reduce shrinkage?
Well, it's not realistic to totally eliminate "unplanned" shrinkage, however, in most cases in can be reduced to an acceptable level. One major reason for "unplanned" shrinkage is out-of-adherence. Often, call centers don’t have the necessary visibility into what happens at any moment in time and what is supposed to happen based on the published schedule.