Multi-objective optimization design for safety system based on isolation-inoperability competing failure mechanism

In order to avoid single indicator ̄based design flawꎬ a multi ̄objective optimization design method of safety system based on isolation ̄inoperability competing failure mechanism was proposed. Considering that the core of this method was thresholds setting of isolation component and inoperability componentꎬ three performance indicesꎬ including PLOASꎬ reliability lossꎬ mass costꎬ were utilized to express influence of thresholds setting on system safetyꎬ reliabilityꎬ and mass respectively. On this basisꎬ a relevant multi ̄objective optimization function was establishedꎬ and linear weighted method was applied to converse multi ̄objective optimization problem to a single one. The results show that the proposed method is suitable for solving multi ̄objective optimization problem based on isolation ̄inoperability competing failure mechanismꎬ and Pareto solution sets can be obtained not only for three objectives optimization problemꎬ 中 国 安 全 科 学 学 报 China Safety Science Journal 第30卷 2020年 but also for two objectives optimization problem under strong restriction of safety.