A Method for the Computation of Reliability Bounds for Non-repairable Fault-tolerant Systems

A realistic modeling of fault-tolerant systems requires to take into account phenomena such as the dependence of component failure rates and coverage parameters o n the operational configuration of the system, which cannot be properly captured using combinatoric techniques. Such dependencies can be modeled with detail using continuous-time Markov chains (CTMC’s). However, the use of C T M C models is limited by the well-known state space exploition problem. In this paper we develop a method f o r the computation of bounds f o r the reliability of non-repairable faulttolerant systems which requires the generation of only Q subset of states. The tightness of the bounds increases as more detailed states are generated. The method uses the failure distance concept and is illustrated using a n exumple of a quite complex fault-tolerant system whose failure behavior has the above mentioned types of dependencies.