customer average interruption duration index (CAIDI)

Customer Average Interruption Duration Index (CAIDI) is a characteristic value for the supply reliability ofpower supplies.

The CAIDI index is the average interruption duration. It is the time during which the electricity customer does not get electricity.

The average interruption duration is calculated from the ratio of the average unavailability, System Average Interruption Duration Index( SAIDI), and the interruption frequency, System Average Interruption Frequency Index( SAIFI), and usually refers to a period of one year. The CAIDI value is given in minutes.

The SAIDI value is defined in IEEE Standard 1366 from 1998.