Service Level Metrics and Management
By Penny Reynolds
There are several ways for a call center to define its speed of answer goals and many factors involved in determining what the quantitative service objective should be.
There are two primary ways to define speed of answer or delay time in a call center. These definitions are service level and average speed of answer (ASA).
The most common way to define speed of answer is service level. Service level is noted by X% of calls answered in Y Seconds. The table on page 10 shows a distribution of calls and wait times for a simple, two-person queue in a 30-minute window of time.
In this example, one can easily see the percentage of calls handled in less than any given wait time. If the desired wait time was 20 seconds or less, then simply note the number of calls that wait 20 seconds or less in queue compared to the total number of calls. In this example, nine of the fifteen calls meet this guideline, so the resulting service level would be 60% in 20 seconds.
The other way to describe speed of answer is average speed of answer or ASA. This number represents the average delay experienced by all calls during the period, including the ones that get handled immediately with no wait in queue. In the 8:00 – 8:30 example shown here, the ASA is calculated by taking the total delay for the period of 336 seconds divided by the 15 calls to arrive at an average delay of 22.4 seconds.
Setting Service Goals
Defining a speed of answer or service objective is an important part of the workforce management process as it has a direct influence on how many staff will be needed each half-hour. There is absolutely no such thing as an “industry standard” for speed of service. Each call center’s service goal should be based on many different factors, including the following:
Customer expectations. First and foremost, the customer contact strategy, including the setting of speed of answer goals, should be based on customer needs and expectations. Customer expectations are today being based on a wide variety of service experiences, and it is important to consider these in defining a service goal to meet customer expectations. Customers should be surveyed regularly to see what their service expectations are in terms of both quality and speed of service. It may be appropriate to have faster speed of answer goals for some customers than for others rather than having one goal that applies to all calls.
Competitive influences. Certainly, most call centers will want to also benchmark against what similar companies are doing and how quickly they are responding to customer contacts. To some degree, the call center may base its speed of answer goals upon how captive its customer base is. If part of a highly competitive industry where callers have many options for service, the call center may wish to set more aggressive service goals, while those with a monopoly on a product or service may settle for less strenuous ones. Even in a single center, multiple situations may exist. For example, an automobile insurance company may want fast speed of answer on the sales lines, but not such an expensive goal for staffing in the claims processing department.
Market position and branding. In some cases, speed of answer may support the overall brand image and reputation of a company. Those organizations known for speedy service may wish to set high service level goals to support the company’s brand image.
Budgetary guidelines. Ideally, service objectives should drive staffing requirements and the budget. But in reality, service objectives may be driven to some degree by available budget dollars. While a call center might like to deliver a 90% in 10 seconds speed of answer, there may simply be insufficient budget to support such a high goal, and therefore the objectives should be set to a level that is actually attainable by the center.
There are many factors that should be considered in establishing a speed of answer goal and careful consideration should be given to this number since it dictates resource requirements and a significant portion of the call center’s operating budget. Careful thought should be given to this objective on a regular basis to ensure the objectives make sense in terms of budget dollars, customer expectations, and support of the company’s mission and goals. Too often call centers set service goals and then never think about them again even as the business grows and changes. It is recommended that service objectives be evaluated at least every two years, with an annual review being the preferred timeframe.
|Arrival Number||Time of Arrival||Handle Time||Time Call Began||Time Call Ended||Delay of Call|
|3||8:03.6||2.0||8:04.6 a||8:06.6||60 sec|
|4||8:04.3||3.2||8:05.0 b||8:08.2||42 sec|
|6||8:06.8||2.4||8:08.2 a||8:10.6||84 sec|
|7||8:07.2||3.0||8:09.0 a||8:12.0||48 sec|
|8||8:10.1||1.2||8:10.6 b||8:11.8||30 sec|
|14||8:26.2||2.4||8:27.2 a||8:29.6||60 sec|
|15||8:28.0||2.4||8:28.2 b||8:30.6||12 sec|
There are many options for reporting speed of answer numbers, either as service level or ASA. Some of these common reporting approaches are problematic as they present a picture of service that is not necessarily representative of the customer experience.
One option is to simply review and report the simple average of service level or ASA at the end of the day. As a simple average, the end-of-day service level for the day noted in the chart on page 11 would be 82%. With a goal of 80% in 20 seconds, it at first looks like the day was a success in terms of meeting service goals. However, a closer look shows that the 82% number averages out quite a few highs of 100% with lows of 65%, with all hours weighted equally. This really overstates the actual service picture for the day.
Another approach is to evaluate and report the numbers as a weighted average for the day, using each hour’s percent distribution of calls. Using this approach, the service level for the day was 79%, another number that suggests a successful service day. While a better approach than a simple average, it still does not provide any information about the variation of lows and highs for the day.
More call centers today are using an interval approach to evaluate speed of answer success over a day. In this example, look at the number of intervals that actually met the 80% service goal. Even with this simple an observation, there can be several ways to measure. Some centers might view any hour with 80% or higher as a positive. If counting this way, there are 8 of the 12 hours that meet these criteria. However, it could be argued that an hour with 100% service level is overstaffed with too high a level of service. By having too many staff in place in some hours, there may not be enough to go around during busier times.
A preferred approach is to look at the percentage of intervals in the day that meet the actual target service level within a reasonable range. This might be within 10% (70% – 90%) or a more stringent criterion of within 5% of target (75% – 85%) to count as a successful period.
Looking at service level in this way will actually provide more actionable information to see where overstaffing and understaffing occur. This forces a more active look at the forecast accuracy for the intervals that are off, or perhaps at some different schedule plans that provide better coverage with less variation.
Managing a call center means managing by the numbers andone of the most important numbers that drives major decisions on the long-term planning side as well as the day-to-day management of the center is the speed of answer. Whether service level or ASA is used as the primary goal and measure, it is important to regularly review the target to make sure it makes sense. Ongoing review of service performance should be done in a way that provides a realistic view of what is happening with numbers presented in a way to identify gaps and make needed changes.
Daily View of Service Level
|Time of Day||Call Volume||Daily %||SL (in 20 sec)|
|6:00 – 7:00||85||4.5%||100%|
|7:00 – 8:00||90||5.0%||95%|
|8:00 – 9:00||95||5.5%||95%|
|9:00 – 10:00||145||8.0%||90%|
|10:00 – 11:00||185||10.0%||75%|
|11:00 – 12:00||195||10.5%||70%|
|12:00 – 1:00||165||9.0%||80%|
|1:00 – 2:00||185||10.0%||80%|
|2:00 – 3:00||220||12.0%||65%|
|3:00 – 4:00||210||11.0%||70%|
|4:00 – 5:00||145||8.0%||80%|
|5:00 – 6:00||125||6.0%||85%|