Analysis of fault tolerant systems operating under different stress levels during a mission

Derives expressions for performance availability and performance reliability of fault tolerant systems operating under various levels of stress during a mission using stochastic reward models (SRM). Develops a mathematical model using semi‐regenerative reward model. Obtains a system of convolution integral equations satisfied by various state probabilities corresponding to different initial conditions. As a particular case, analyses a 3‐unit parallel system under three different stress levels. Uses an iterative numerical method to solve the system of integral equations satisfied by various state probabilities to study the effect of parameters on various system performance.