The ASA calculation used for vector routing is called Rolling ASA to differentiate it from the Interval ASA that is recorded in Basic Call Management System (BCMS) and Avaya Call Management System (CMS) reports.

Rolling ASA is a running calculation that does not take into account the 15-minute, half-hour, or hour reporting intervals. Rolling ASA does not reflect interval boundaries.

The Interval ASA used for BCMS and CMS reports is calculated on reporting interval boundaries and clears to zero at the start of each reporting interval.

The Rolling ASA for a split or VDN is calculated based on the speed of answer for all calls recorded since system start up and is recalculated every time a call is answered. During each calculation, the speed of answer for the current call is given a weighted value that is greater than previous calls. Approximately 95 percent of the value of Rolling ASA is retrieved from the previous ten calls.

The Rolling ASA is calculated for an entire split or VDN. The calculation does not include the priority levels of answered calls.