Steady-State Reliability of Systems of Mutually Independent Subsystems

Predicting the reliability of a redundant system with repair is considerably simplified when the system can be subdivided into mutually independent subsystems. Results can be obtained without knowing the failure of repair time distributions of the subsystems. In this paper formulae are developed for the ``steady-state´´ availability and MTBF of a complex system in terms of the availabilities and MTBF´s of its constituent subsystems. The basic concepts required are introduced and discussed in a review of a simplex system. These concepts are then applied to a complex system to obtain the main results of the paper. Finally, two examples are given to illustrate the application of these results.