A lifetime prediction approach for parallel standby systems with stochastically degrading spare parts

As the key part of prognostics and health management (PHM), lifetime prediction has been recognized as an effective technology to guarantee reliable, safe and economic operation for key industrial systems. Despite that there are various parallel standby systems in the industry, most exiting researches concerning the lifetime prediction of parallel standby systems ignore the degradation of spare parts in storage, resulting in inaccurate lifetime prediction and unreasonable management arrangement. Therefore, this paper proposes a lifetime prediction approach for parallel standby system with multiple stochastic degrading spare parts of the same type. On the basis of a two-phase Wiener process, the stochastic degradation models for operating parts and stored spare parts has been constructed. Then, the reliability function and lifetime probability density function (PDF) of the system have are derived, integrating the impact of the replacement strategies. Finally, the proposed approach has been demonstrated by a simulation study, where the lifetime PDFs of parallel standby systems under three different replacement strategies are provides and verified.