Influence of storage on mission success probability of m-out-of-n standby systems with reusable elements

Abstract

Recent studies have shown that elements reusing through preventive replacements is beneficial in enhancing the mission success probability (MSP) of standby systems. While storage is often an essential unit for system functions, none of the existing works on standby systems with reusable elements have considered this unit in the system modeling and analysis. We make contributions by modeling and optimizing a m-out-of-n standby system with reusable elements and an imperfect storage unit. The system performs a mission task that must satisfy a pre-specified demand during the mission time. Surplus product produced by operating elements is stored; in the case of not meeting the demand, the storage unit, if available, supplies the saved product to compensate the deficiency. All the system elements, during their idle time, may undergo different types of actions including staying in the warm standby mode, being protected, undergoing imperfect or perfect maintenance. A probabilistic modeling approach is first proposed for assessing the MSP of the considered system. The optimal operation and maintenance schedule (OMS) problem is then formulated and solved, which determines the OMS maximizing the MSP. A case study on a standby power generation system is provided to demonstrate influences of several storage parameters (storage capacity, storage reliability, and storage activation procedure reliability) on the MSP and optimized OMS solutions.