Call center operations are changing, and customer expectations are higher than ever. Holding for 20 minutes only to have an issue left unresolved is no longer acceptable. Customers are contacting call centers via phone, email, text message, instant message and social media. They expect a fast response and an effective solution delivered through the channel of their choosing. As a result, human interaction is retaking center stage in the call center, pushing automated responses to the background.Having just the right number of call center agents is critical to delivering the best possible customer experience while improving efficiency and controlling costs. Properly calculating call center staff requirements is a critical component of transforming the call center from a cost center to a profit center.

The first step is to calculate the workload. This begins with analyzing broad trends for incoming calls. Start with seasonal and monthly trends. Then analyze data based on specific days of the week and hours of the day. This will enable you to create call forecasts for every hour or half hour.

You also need to determine the average handle time, which is comprised of the interaction time and any follow-up tasks, such as an update to the customer's history. Average handle time will vary based on time of day and day of week. The more precise your calculations are, the more efficient your call center will be.

To determine the workload, you multiply the number of forecast calls by the average handle time. For example, suppose you forecast 200 calls during the 9 am hour with an average handle time of three minutes. That's 600 minutes, or 10 hours of workload.

Assuming calls are handled sequentially, the call center would require 10 agents to handle 10 hours of workload in during the 9 am hour. In a perfect world, that may be the case.

In reality, call center workloads are very random. You may receive 200 calls over the course of the hour, you may get 30 of those calls within the first five minutes. That's why it's important to allocate more staff hours than the number of hours of work to be done.

When calculating call center staff requirements, many companies use the Erlang C model, which accounts for random workloads and hold times. Based on the number of calls per hour, call duration and the average delay, Erlang C predicts what will happen in the call center based on a certain number of staff members.

Using the previous example, we know that you would need more than 10 agents to handle 10 hours of workload. Erlang C can tell you how call center performance would be impacted by having, for example, 12-15 agents available.
For each number of agents, Erlang C would tell you:

• The percentage of customers that would go into a queue (on hold)
• The average delay time for calls in the queue
• The average delay time for all calls, including those answered immediately
• The percentage of calls handled within a specified period of delay time

Click here to try using the Erlang C calculator.

The number of additional call center staff members is based on your service goals and acceptable delay time. There is no industry standard, so service goals are based on business objectives, standards of competitors, agent feedback and, most importantly, customer demands. Never lose sight of the fact that the call center can have a direct impact on your bottom line - positive or negative - depending on how well you meet customer expectations.