Reliability analysis of cold standby system with scheduled backups

Cold standby technique is one of the most commonly applied techniques to achieve high reliability requirement of modern products. This paper studies a 1-out-of-n cold standby system, where scheduled backups are performed to ensure that a standby component can take over the task effectively when the online component fails. Since a component may fail during switching from the cold standby state to the online state, effect of imperfect switch is also considered. Lifetimes of components in the considered system can follow arbitrary distributions and are not necessarily identical. Backup intervals are deterministic but can be non-identical. A multivalued decision diagram (MDD)-based analytical approach is proposed to evaluate reliability of 1-out-of-n cold standby systems subject to scheduled backups. Illustrative examples are provided. Correctness of the proposed method is verified using Monte Carlo simulations.