Testing strategies for parallel-series standby systems

Surveillance test schedule has been studies to increase standby system unavailability and keep plant safety. In earlier research, testing strategies, such as simultaneous or uniformly staggered testing, have been applied for simpler standby systems and the optimal test interval can then be obtained. For more complex systems, the best testing schedules were obtained by comparing the performance of pre-specified testing policies by using computer software or simulation. In this study, three candidate testing strategies for parallel-series systems were developed based on the results of simpler systems. The performances of three candidate strategies are also been compared under both risk (considering only system unavailability) and decision (considering both system unavailability and maintenance cost) points of view.