Average Service Availability Index Explained

The Average Service Availability Index (ASAI)^{[1] [2]} is a reliability index commonly used by electric power utilities. ASAI is calculated as

ASAI = (\sum{N _{i})/(x) 8760 - \sum{U _{i} N _{i}}{\sum{N} _{i}} x 8760 }

where

N _{i} is the number of customers and U _{i} is the annual outage time (in hours) for location i . ASAI can be represented in relation to SAIDI (when the annual SAIDI is given in hours, 8760 is the number of hours in a year)ASAI = 1 - (SAIDI)/(8760)

Notes and References

1. Web site: Distribution System Reliability Evaluation . Sree . Yeddanapudi . Iowa State University . 18 June 2011 . dead . https://web.archive.org/web/20111226034249/http://www.ee.iastate.edu/~jdm/ee653/DistributionReliabilityPredictive.ppt . 26 December 2011 .
2. Book: Pham, Hoang. Handbook of reliability engineering. 21 July 2011. 8 April 2003. Birkhäuser. 978-1-85233-453-6. 514.