Nortel Express User Manual page 18

Getting started
Service level
The service level is the percentage of incoming calls answered within a specified
number of seconds. For example, you may have the objective, "80 percent of
calls are answered within 20 seconds." In this case, your service level is 80
percent and your threshold time is 20 seconds. Your actual service level,
reported by Symposium Express Call Center, may be "77 percent of calls are
answered within 20 seconds." The server uses the following equation to
calculate service level:
{[(Calls Answered + Calls Abandoned) – (Calls Answered After Threshold +
Calls Abandoned After Threshold)] * 100} / (Calls Answered + Calls
Abandoned)
where the threshold is the number of seconds defined in your service level
objective (for example, 20).
Example
Your call center receives 80 calls in one hour:
10 calls are answered after the threshold
!
20 calls are abandoned
!
13 of the abandoned calls are abandoned after the threshold
!
In this case, the service level is
{[(80+20)–(10+13)]*100}/(80+20) = 77%
18
Standard 2.0
Symposium Express Call Center