ASUI

The Average Service Unvailability Index (ASUI) is a reliability index commonly used by electric power utilities. It is calculated as

${\mbox{ASUI}}={\frac {\sum {U_{i}N_{i}}}{\sum {N_{i}}\times 8760}}=1-{\mbox{ASAI}}$

Or in relation to SAIDI (where annual SAIDI is given in hours)

${\mbox{ASUI}}={\frac {\mbox{SAIDI}}{8760}}$

where $N_{i}$ is the number of customers and $U_{i}$ is the annual outage time (in hours) for location $i$.

See also

• ASAI
• SAIDI
• SAIFI
• CAIDI
• CAIFI
• MAIFI