Optimal inspection models with minimal repair

Although the logistics support is indispensable in maintaining defense systems, there may exist some situations that systems have to be operated in no logistics support and maintenances of systems are performed with constraint stocks. Although repairing by brand-new parts improve system reliability, repairing by degraded parts may not disturb the system failure rate and such maintenance is called minimal repair. The minimal repair maintenance is common for warships in the long voyage because their repair parts inventories are limited and degraded parts have to be exploited. Although system failures can be detected because the system operates peculiarly that the operator does not wish, some failures cannot be detected in operation and they are detected only by diagnoses. In this paper, these two types of failures should be considered when we plan the military system maintenance. Optimal inspection policies of two types of failures with minimal repair are proposed.