BPO Articles - The Call Center Staffing

Over two-thirds of call center operating costs are related to personnel, and thus getting just the right number of staff in place each hour to respond to customer contacts is critical in terms of both service and cost. Correctly managing this number is the key behind successfully running a call center operation. This article helps in understanding Staff and Service Tradeoffs and outlines the step-by-step process to calculate call center resource requirements.

How to calculate the Workload?

Staff workload is simply the number of forecast calls for an hour multiplied by the average handle time of a call. We can forecast calls by taking the historical data and then analyzing trends and seasonal patterns to arrive at monthly estimates. And similarly by using day-of-week and time-of-day patterns, we can break down the numbers into hourly or half-hourly forecasts. The average handle time (AHT) is made up of two components: actual conversation or talk time plus any after call wrap-up time associated with the call. The wrap up time consists of the time required for filling out a form, updating the customer database, etc.

This handle time is likely to vary by time of day as well as by day of week. For example, you may find that AHT is higher during the evening shift since you may have newer staff working the undesirable hours, or simply have callers that like to talk a little longer during the wee hours of the morning! Most call centers simply use an average number for handle time, which may be a dangerous assumption if there is a 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.

This workload is then used to determine how many base staff is 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 a group of clerical workers processing mail in the same company. Between 8:00 and 9:00am, the clerical staff has 400 pieces of mail to process and each piece takes 3 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?

The answer is: to process 20 hours of workload, 20 staff would be needed. The reason for the 1:1 ratio is that the mail tasks represent sequential workload. In other words, the staff can process the work as back-to-back tasks and each person can accomplish one hour of work in an hour timeframe.

Determining the Call Center Staff Requirements

Now considering the staff for the call center. These employees are getting 400 calls and each one takes an average of three minutes to handle – 2 minutes of conversation and another minute of after-call work. Again, this comes out to be 1200 minutes or 20 hours of workload. So, how many people are needed?

Unfortunately, we can’t handle the calls with only 20 people. At 8:05, there may be 22 calls arriving, meaning all 20 agents are busy, with another 2 calls in queue. Then at 8:15, there may only be 16 calls in progress, meaning 4 of our staff are idle. Those 4 people won’t be able to accomplish a full hour’s work, simply because of the way the calls have arrived. In an incoming call center, the work doesn’t arrive in a back-to-back fashion. Rather, the work arrives whenever our customers decide to place calls. So we have random workload instead of sequential work. This brings us to the conclusion that you must have more staff hours in place than hours of actual work to do.

So how many extra do we need? For 20 hours of workload, will we need 21 staff? 24? 30? Actually, the number of staff needed depends on the level of service we wish to deliver. Obviously, the more staff we have, the shorter the delay. The fewer the staff, the longer the caller will wait.