Circuit reliability

Circuit reliability (also time availability) (CiR) is the percentage of time an electronic circuit was available for use in a specified period of scheduled availability. Circuit reliability is given by

${\displaystyle T_{s}=T_{a}+T_{o}}$

where ${\displaystyle T_{o}}$ is the circuit total outage time, ${\displaystyle T_{s}}$ is the circuit total scheduled time, and ${\displaystyle T_{a}}$ is the circuit total available time. In addition, circuit reliability is the expected lifespan of operation of a functioning system under nominal conditions.