Here’s a nice little source for ideas on how to measure telephone service:
http://www.the-cma.org/?WCE=C=47%7CK=227275
it explains 10 call centre metrics, amongst which:
Abandon Rate: the number of calls that hang-up before connecting to an agent. This number does not include those calls that receive a busy signal.
Calculation: Abandoned Calls / Total Incoming calls
Service Level: usually defined as the percentage of calls answered within a predetermined number of seconds.
Average Speed of Answer: (commonly referred to as ASA) is the average number of seconds it takes for a call to be answered.
First Call Resolution: measures the percentage of customer issued calls that are resolved the first time.
Calculation: Number of FCR calls / Total Number of Calls
