Reliability Evaluation of a System Protected by Blocks

Abstract

We model the reliability of a system with a main component and two auxiliary components for protection, one active, the other on cold standby. The main component performs the system function. The auxiliary components are called protection blocks. The failure rate of the main component depends on whether it is protected or not. The blocks have their own constant failure rate, that is, their lifetimes are exponentially distributed. The reliability of such a system is obtained and the properties of its failure rate are investigated. A necessary condition is obtained to compare the cost-e¤ectiveness of single and two-block protection. Likewise, we obtain necessary conditions for comparing the e¤ectiveness of di¤erent three-component designs under the mean time to failure criterion. In this way, the work provides decision support for the designers of systems protected by blocks.