Occupancy vs. Speed of Answer Goals

By Maggie Klenke

Balancing customer service expectations with the demand for efficiency is challenging. While the speed of answer goals (service level or average speed of answer) are generally the drivers of the planning and scheduling process, cost-effectiveness often drives the budget and hiring plan. At the same time, finding schedules and daily adjustment processes that meet the needs of agents can add to the complexity. All these elements are in constant flux as the workload changes from hour to hour and day to day. To find the best balance, tradeoffs between these goals need to be understood by not only the workforce planners, but by agents and management as well.

Speed of Answer

Let’s start with the workload since everything else revolves around it. It is the number of units of work (calls, emails, chats, etc.) that must be completed in a set timeframe multiplied by the average amount of time it takes to complete each task. For example, if the call handling team receives 120 calls in a half-hour period and each call takes 300 seconds to complete on average (including talk and after call work), then the workload for that period is 20 Erlangs or workload hours (120 x 300 / 1800). That means that there must be at least 21 people available during that hour to answer those calls. But with only 21 people, the speed of answer is likely to be unacceptable to the callers. More people will be needed to answer the phone more quickly, and that means spreading the same workload among more people. With each additional person taking calls, the speed of answer will improve, but the trade-off is that each person will be less occupied with those calls and have more idle time between them. (See table below.)

Workload Hours

Number
of Staff

ASA

Service Level (% in 30 sec)

Staff Occupancy

20

21

137 sec.

35%

95%

20

22

51 sec.

59%

91%

20

23

25 sec.

75%

87%

20

24

13 sec.

85%

83%

20

25

7 sec.

91%

80%

20

26

4 sec.

94%

77%

Occupancy

Occupancy is defined as the percentage of the period that the agent is actually handling the incoming calls. This includes the talk time and the after-call work time but not the idle/available time between calls or time spent doing any other type of work. Therefore, if the workload keeps the agent busy with calls for 50 minutes out of an hour, then the occupancy percentage is 83%. A common question is “what is the ideal occupancy percentage?” but there is no good answer. If it is too low, agents have a lot of idle time and may be bored, and quality can suffer. If the agents are too busy with no rest time between calls, they can be overwhelmed. Given the way the workload fluctuates within a day and the over- or under-scheduling that can occur because of scheduling rules and desires, the agents might be occupied at 100% during some busy periods and at 60% during others. Even days of the week can vary significantly if the workload is higher on some days and most/all staff are full-time with rigid scheduling rules. For example, a small operation that is open 8AM to 5PM five days per week with all full-time staff can be significantly understaffed on the busiest day and overstaffed on the lightest.

Tradeoffs

Since most call center schedule planning is driven by the workload demand and speed of answer goal, the occupancy of the agents is a result of this plan. If higher occupancy is the primary goal but workload remains constant, then agents will need to be removed from the schedule and that will increase the percent of time each agent is handling calls at the expense of the speed of answer. It is like one is on each end of a child’s teeter totter. If one goes up, the other goes down. The only way to modify this effect is to change the workload that the team is handling. This can be done by cross-training staff to handle more types of calls, networking sites together, or using skill-based routing to deliver more work to the same people. Larger teams are naturally able to handle a larger workload with the same speed of answer since each time an agent becomes available, calls will be more likely to be available in the queue. And with more agents doing the work, there is a higher likelihood that the next call will find an agent more quickly as well. (See following table.)

Calls/Hour

Staff Workload

Number of Staff

Occupancy Level

Service Level

400

20 hours

23

87%

75%

400

20 hours

24

83%

85%

400

20 hours

25

80%

91%

800

40 hours

44

91%

78%

800

40 hours

45

89%

85%

800

40 hours

46

87%

90%

1600

80 hours

85

94%

79%

1600

80 hours

86

93%

85%

1600

80 hours

87

92%

89%

At about 100 agents in a single team, the gains from combining staff are fully exploited and individual occupancy will leave little time to take a breath between calls. The demand to lower occupancy may be felt as agents reach the burn-out stage. But the balance remains the challenge. Lowering occupancy requires more agents to spread the workload and efficiency is reduced. Finding something productive for agents to do between calls that they can drop as a call is delivered may be an option. Perhaps there is email to handle or research to be done. But agents must remain in the available state to drop this work and take the next call immediately or the speed of answer will suffer. Automatic call delivery to the headset and carefully managed use of the after call or Not Ready work state are essential to success.

Intraday management of the match of staff to workload is also important. As the call volume changes, it is challenging to adjust the staffing to keep an exact match. Adding and subtracting staff throughout the day is disruptive and forecasting at that level is generally less accurate. Agents expect a relatively stable shift assignment. If the end goal is to have enough people during the busiest periods to consistently meet the service goal, then other periods may be overstaffed. Taking agents off the phones to have meetings, training, or sending them home may find them unavailable when the workload goes back up. Alternatively, the plan may sacrifice speed of answer during the busy periods to find an average staffing across the day that is more efficient.

Summary

As always in workforce planning, accurate forecasts and high levels of schedule flexibility are key to success in managing the best balance of customer service, efficiency, and agent satisfaction. Understanding the trade-offs of competing goals is essential to the planning and management to achieve the best results. Agreement among all interested parties in setting the expectations will help to minimize intraday adjustments and ensure meaningful communications as well. Human Resources can hire for the best fit, scheduling can build the most accurate plan to utilize the resources effectively, and management will have fewer surprises.

Maggie Klenke is one of the founders of The Call Center School (now retired) and an active industry consultant, assisting contact center clients in development of strategic and tactical plans, technology applications, forecasting and scheduling optimization, service level analysis, and overall management issues. Maggie teaches seminars on a wide variety of call center topics and is a popular speaker at industry conferences in the US and abroad. She may be contacted at maggie.klenke@mindspring.com or 615-651-3324.