The Math of Contact Center Staffing
By Penny Reynolds
Calculating Resource Requirements and Understanding Staff and Service Tradeoffs
Sharpen your pencils. Dust off the calculator. It's time for a math lesson.
Running your catalog's call center operation means managing by the numbers. And the most important number of all is the number of bodies in seats each hour to respond to customer contacts. Since over two-thirds of call center operating costs are related to personnel, getting the "just right" number of staff in place is critical in terms of both service and cost. This article outlines the step-by-step process to calculate call center resource requirements and evaluate the most important service, productivity and cost tradeoffs.
With a call volume forecast and some assumptions about average handle time (AHT), you can perform a simple calculation to arrive at staff workload. It's simply the number of forecast calls for an hour multiplied by the average handle time of a call. The AHT is made up of two components: actual talk time plus any after call wrap-up time associated with the call. The wrap up time can include almost anything - filling out a form, updating the customer database, etc.
This handle time will likely vary by time of day as well as by day of week. For example, you may find that AHT is higher during the night shift since you may have newer staff working the undesirable hours, or you may have callers that like to talk a little longer during the evening hours. Most call centers simply use an average number for handle time across the board, which may be a dangerous assumption if there's significant variance. Imprecise numbers can contribute to the understaffing or overstaffing, so it's best to use numbers that actually reflect time-of-day or day-of-week patterns.
The workload number is then used to determine how many base staff are needed to handle the calls. The part that makes staffing for a call center different than any other kind of staffing situation is that this workload doesn't represent typical work patterns. Let's compare an incoming call center to staff processing mail orders across the hall from the call center. Between 8 a.m. and 9 a.m., the mail group has 400 orders to process and each one takes three minutes to handle. That's 1200 minutes or 20 hours of workload. How many people need to be working to accomplish all the work by 9:00?