Extended age maintenance models and its optimization for series and parallel systems

In this paper, extended preventive replacement models for series and parallel system with n independent non-identical components are proposed. It is assumed that the system suffers from two types of failure. One is repairable (type-I) failure, at that time the system can be rectified by minimal repair. Another is non-repairable (type-II) failure, then the whole system is replaced. In the proposed models, the system is replaced at the planned time, at random working time, or at the time when type-II failure occurs, with options whichever occurs first or whichever occurs last. The average cost rate (ACR) function and the failure rate function (FRF) of the series and parallel system under the different cases are obtained respectively. Moreover, the optimal preventive replacement time of models based on minimization of the ACR function is obtained theoretically. Numerical examples are presented to evaluate the cost of the system and verify the performance of our results.

Automated summary

In this paper, extended preventive replacement models for series and parallel system with n independent non-identical components are proposed. The models consider two types of failure and offer different options for replacement. The average cost rate function and failure rate function under different cases are obtained. The optimal preventive replacement time based on minimizing the average cost rate function is also determined. Numerical examples are provided for cost evaluation and performance verification.