"CAIDI," or the customer average interruption duration index, represents the average interruption duration or average time to restore service per interrupted customer. CAIDI is expressed by the following formula:
CAIDI equals sum of customer interruption durations divided by total number of customer interruptions
"SAIFI," or the system average interruption frequency index, represents the average number of interruptions per customer. SAIFI is expressed by the following formula:
SAIFI equals total number of customer interruptions divided by total number of customers served
Ohio Admin. Code 4901:1-10-10
Five Year Review (FYR) Dates: 9/30/2026
Promulgated Under: 111.15
Statutory Authority: R.C. 4905.22, 4905.04, 4928.06, 4928.11
Rule Amplifies: R.C. 4905.06, 4905.22, 4905.28, 4928.11
Prior Effective Dates: 07/01/1999, 09/18/2000, 01/01/2004, 06/29/2009, 12/20/2014, 11/01/2021