Stochastic Behavior of a Standby Redundant System

The system has two subsystems, A and B. Subsystem A is a 2-out-of-(n+1):F system with switch failure; subsystem B has only one unit. Failure-time distributions of units are exponential whereas repair-time distributions are arbitrary. Abundant use of semi-Markov process technique is made to obtain mean time to system failure, steady-state availability, s-expected number of visits to a state, second moment of time in an up state and s-expected profit.