考虑不完美维修的定期检测与备件策略联合优化

针对退化过程服从三阶段故障过程的单部件系统提出了定期检测与备件订购策略联合优化.该策略下,根据检测时系统的状态执行不同的维修活动:当系统处于正常状态,不执行任何维修活动;若识别轻缺陷进行不完美维修并采用比例役龄回退模型描述不完美维修效果;若识别严重缺陷则更换系统.当更换系统时需考虑备件状态:若处于存货状态则立即更换,若正处于途中则到货时更换,若未订货需立即订货并在到货时刻更换.考虑所有更新事件采用更新报酬理论建立以最小化单位时间内期望成本为目标的模型,同时优化检测周期和订货点.最后,设计枚举优化算法和离散仿真算法求解模型,并在算例分析中验证模型的有效性和适用性.

Joint optimization of periodical inspection and spare parts policies considering imperfect maintenance

This paper proposed a joint periodical inspection and spare parts policy for a single-unit system subject to a three-stage failure process. In such a policy different maintenance activities are performed depending on the state of the system at inspections. When the system is in the normal state, do nothing; imperfect maintenance (IPM) is performed once a minor defect is found and the proportional age reduction model is adopted to describe the effect of IPM; however, once a severe defect is detected the system should be replaced. The spare parts state should be considered if the replacement is required for the system, and there are three different scenarios. The first is that spare parts are available such that replacement can be carried out immediately, the second is that spare parts have been ordered but not delivered so a delayed replacement is performed till the arrival time of spare parts, and the last is that no spare parts are ordered then an immediate order is placed and replacement till the arrival time of spare parts. The objective function minimizing the long-run expected cost per unit time is developed by considering all possible renewal events using the renewal award theorem in order to optimize the inspection interval and the ordering point. Finally, the enumeration optimization algorithm and discrete simulation algorithm are designed, respectively; and the effectiveness and applicability of the proposed model are illustrated by a numerical example.