Definitions

• SAIFI: System Average Interruption Frequency Index (Average interruption rate) - Total # of customers affected/total # of customers served.
• SAIDI: System Average Interruption Duration Index (Average duration of interruptions) - Sum of all customer interruption durations/total # of customers served.
• CAIDI: Customer Average Interruption Duration Index (Average repair time of interruptions) - Sum of all customer interruption durations/total # of customers affected.
• CEMI: Customers Experiencing Multiple Interruptions - Percentage of customers that experience 3 or more interruptions in a 12-month period.
• CELID: Customers Experiencing Long Interruption Duration - Percentage of customers that experience one or more interruptions of 7 hours or more in a 12-month period.