CAIDI

The Customer Average Interruption Duration Index (CAIDI) is a reliability index commonly used by electric power utilities. It is related to SAIDI and SAIFI, and is calculated as The Customer Average Interruption Duration Index (CAIDI) is a reliability index commonly used by electric power utilities. It is related to SAIDI and SAIFI, and is calculated as CAIDI = ∑ U i N i ∑ λ i N i {displaystyle {mbox{CAIDI}}={frac {sum {U_{i}N_{i}}}{sum {lambda _{i}N_{i}}}}} where λ i {displaystyle lambda _{i}} is the failure rate, N i {displaystyle N_{i}} is the number of customers, and U i {displaystyle U_{i}} is the annual outage time for location i {displaystyle i} . In other words, CAIDI = sum of all customer interruption durations total number of customer interruptions = SAIDI SAIFI {displaystyle {mbox{CAIDI}}={frac {mbox{sum of all customer interruption durations}}{mbox{total number of customer interruptions}}}={frac {mbox{SAIDI}}{mbox{SAIFI}}}}