失效不能立即被发现的2参数预防维修策略

研究了一类失效不能立即被发现的2参数预防维修策略，即系统在失效时刻不能立即被发现，故不能在失效时刻被更换，而是等到下次预防维修时刻进行更换，从系统失效到被更换有一失效等待.利用几何过程，建立了一个2参数预防维修策略(L,N)，并通过数值实例得到了相应的最优维修策略(L,N)*，使系统经长期运行单位时间期望费用最小.

Preventive Repair Policy with Two Parameters for Failure Waiting of a Repairable System

This paper studies a preventive repair policy with two parameters (L,N) for failure waiting time.It is  assumed that when the system fails,it will be replaced in the next preventive repair time rather than at once,and so there will be a failure waiting between failure time and the replaced time.By geometric process,the explicit expression of the average cost rate is derived.Moreover,an appropriate numerical example is given and the optimal (L,N)* policy is derived which makes the average cost rate minimized.