Engineering: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 where T _o is the circuit total outage time, T_s is the circuit total scheduled time, and T _a is the circuit total available time. [math]\displaystyle{ T_s = T_a + T_o }[/math] In addition, circuit reliability is the expected lifespan of operation of a functioning system under nominal conditions.