Optimal preventive switching of components in degrading systems

In practice, at many instances, it is important to maintain the failure-free performance of components in a standby system, as each sudden failure of an operating component can result in a failure of a system, e.g., due to imperfect or/and ‘non-instantaneous’ switching on failure and related adverse effects. Therefore, the scheduled preventive switching/replacement to the standby component that can be executed without these consequences is one of the effective methods for increasing reliability characteristics of such systems, especially in the safety-critical applications. In this paper, the corresponding optimal strategy for switching is described and justified for the cold standby system of two aging components with degradation modeled by the counting Poisson and gamma processes. An inspection is carried out at some optimally predetermined time and based on the observed degradation switching is performed after the optimally obtained delay. Detailed numerical examples illustrate our findings.