The process for calculating shrinkage using the following call center shrinkage formula begins by determining your base staff requirements for typical call volume at each point in a given day or a given shift. Within those calculations, estimate the typical percentage of workers who will be unable to handle calls during the interval. This may vary, but the usual range is somewhere between 10% and 40%.
Do you have the number? Great – now as part of the shrinkage formula, divide your base staff requirement by that result to arrive at the number of workers you should schedule. For example, with a 40% shrinkage rate and 100 call center agents on the day shift, you would divide 100 by (1 minus 0.4), for a total of 167. Now you know that if you schedule 167 people, but 40 percent can’t answer phones for various reasons, the remainder available will be 100, and the phones will be adequately covered.