4 Pitfalls When Measuring Occupancy Rate

This week we present a new installment in our “Pitfalls” series which looks at common mistakes made when measuring or interpreting contact center metrics. Occupancy rate basically measures how “busy” call center agents are when they are at work.

Occupancy is often used as a predictor of “agent burn-out”. Agents need time to take a breath and collect their thoughts between calls. Otherwise, performance suffers, followed by higher absenteeism and, eventually, agent attrition. There is a general consensus that occupancy above 85% is not sustainable. But how do we arrive at that number? It’s driven by the number of calls per agent per day, but, as usual, there are nuances to the calculation that have important ramifications. Let’s look into how to calculate — and use — occupancy rate properly.

Pitfall 1: Not Including After Call Work

Consider an agent who is engaged in call-related work for 45 minutes during a 60 minute period. He has an occupancy rate (or just “occupancy”) of 75%. That’s pretty straightforward, right?

However, we need to look deeper into the phrase “call-related” which is the numerator of the fraction. We have to include more than just “talk time”, because sometimes agents are on hold, during the conversation, waiting on another process. We also need to include work that happens after the call to “wrap-up” the transaction. This is sometimes called “After Call Work” (ACW).  Defining the boundaries between ACW and other non-call work can be tricky. It’s important to limit this to work that is directly related to that particular call, and exclude general non-call work.

In fact, a common way to calculate occupancy rate is to add up all the handle time during the defined time period. For more on the topic of handle time see this post.

Pitfall 2: Not Calculating “Available Time” Properly

Now that we know the numerator of the fraction, what about the denominator? What’s the right way to count how much time the agent was theoretically able to work?

Many contact center systems will report “Available Time” for an agent, which counts the time an agent was logged-in, but not on a call (sometimes called “Idle Time”). With this number, we can calculate occupancy rate:

But beware a pitfall with “Available Time”: It must not overlap with ACW time or on-hold time.

Other call centers are set up to report “Logged In” time for an agent. We can use this instead of Handle Time if we can subtract away all non-call related activities. This time is often labeled “Aux”, “Misc” or “Non-Call”. That leads to an alternate formula:

The danger with this approach is to make sure agents are diligent in setting their status codes properly so that “Aux” covers all the appropriate time.

Pitfall 3: Not Aligning Your Occupancy Target with ASA Target

There is a complicated interaction between occupancy rate and service level. (See 5 Pitfalls when Setting Your Call Center Service Levels.) Given the same number of calls with the same handle time, meeting a higher service level will yield lower occupancy rates, and vice versa. Lowering your target service level means fewer staff is needed, which raises occupancy. Similarly, if speed of answer improves, occupancy will naturally fall, all other things being equal.

The pitfall here is that if you set a speed of answer (ASA) goal that is incompatible with your occupancy goal, you will loose on both fronts. See this spirited discussion on the LinkedIn group, Call Center Professionals for more on this issue.

Pitfall 4: Confusing Occupancy with Productivity

Do not confuse occupancy with productivity. One agent may be able to write-up a summary or send an email faster than another. In this case, the “after call work” would be less and yield lower occupancy for the more efficient agent. It would be wrong to see this “less occupied” agent as a poorer performer.