Abstract
A periodic inspection and replacement policy, considering both the early detection and prevention of equipment failures, is proposed in this paper. The optimization procedure and the property of the optimal solution under the criterion which minimizes the expected cost per unit good time are presented through two theorems and a property respectively. The numerical analysis is also made. The results show that this policy has the trade-off relation between the inspection and the preventive replacement and that the higher the degree of deterioration in the failure mode becomes, the greater the weight of the replacement increases.