一种改进的两单元冷贮备系统保障策略

An Improved Maintenance Policy for a Two-Unit Cold Standby Redundant System

对于采用冷贮备冗余设计的导弹指挥仪，为了满足其高可靠性和可用性要求，提出了预先维修和备件订货的联合保障策略。考虑了以预先维修为主，以改正维修为辅的维修方式，采用了近似的（S-1，S）订货策略满足备件需求。建立了非线性规划模型反映可用性约束和保障费用目标。基于马尔可夫更新过程，推导了期望费用和可用性的公式。算例表明，与参考的策略对比，改进的更换策略能够显著地节省费用。

A certain type of missile director is a cold standby redundant system. To achieve high reliability and availability, a maintenance policy based on preventive replacement was presented. The maintenance policy involved component replacement and spare provision, where preventive replacement and corrective replacement were combined in replacement policy and orders were released when a specified time reached or a failure occurred. A non-linear programming model was established to minimize the average expected maintenance cost subject to the constraint of system availability. Based on Markov renewal process, formulas for expected cost and system availability were derived. Comparison between the improved policy and reference policy were made. Numerical examples indicate that the improved policy can lead to more cost saving.