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  • Writer's pictureTesfahun Tegene Boshe

Headcount requirement vs SLA, AHT and volume

In order to meet the service level objectives, the contact center needs to have an appropriate number of agents, and this number is proportional to the incoming volume of calls, the SLA, and the AHT. These three factors are essential in determining the number of agents required to meet the service level objectives of a contact center.

In this post we will analyze three plots showing the impact of changing one of these three major factors on the headcount requirement. We are assuming contacts of dynamic nature such as phone calls and live chats at 32 contacts per hour, 360 seconds AHT and 80% SLA at 30 seconds SLA time. One of these inputs will change at a time while keeping the others constant.

Service Level Agreement (SLA): The SLA is the agreement between a contact center and its customers on the level of service they will receive. The SLA typically includes a target response time, which is the time within which an agent must respond to a customer inquiry. The lower the SLA target, the more agents required to meet it. The figure below shows how the headcount requirement changes as SLA target increases.

The headcount requirement rises sharply with the service level target. The slope gets sharper at around 90% service level and above. It is, therefore, advisable to target a lower service level (around 80%) to save costs.

Average Handling Time (AHT): AHT is the average time it takes for an agent to handle a customer inquiry, from the time the call is answered until the issue is resolved. The higher the AHT, the longer the customer will have to wait for their call to be answered. The longer the customer waits, the more agents required to handle the volume of calls effectively.

As we can see on the second image, the headcount requirement increases with the handling time. Moreover, the jump in headcount requirement is more significant for an increase in handling time at lower AHT values than similar increase at the other end.

Incoming volume: The volume of incoming calls is the number of calls received by the contact center in a given period. The higher the volume of incoming calls, the more agents required to handle the calls within a reasonable time frame. See below how the headcount requirement behaves as the volume increases.

As we would expect, the required headcount increases with volume. However, headcount requirement does not increase as much as the increase in volume. This phenomenon is called Economy of scale. In other words, having many small queues supported by separate group of agents requires more headcount than if the queues are joint. That is why it is better to create a single team with multiple tasks than many smaller teams with specialized tasks

To summarize this, I hope this blog inspires you to set the right service level and productivity targets as well set your team to a proper size to avoid overspending. I am crazy about applying data science skills to workforce management. Reach me at LinkedIn if you wish to connect :)

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