Decision-making on maintenance for systems with hidden failures

A model of maintenance for a system with hidden failures was developed, which is intended to improve the existing methods of maintenance decision making. In the system, failures may not be observed by the operators of the systems and if the existing hidden failures can not be detected, secondary failure will induced in case some typical failures happen to it. In order to detect the hidden failures, detective maintenance is conducted periodically. For a decision-making on the maintenance work, expected length of a life cycle of the system and costs related to the failures and maintenance are modeled on a basis of analyzing possible events in the life cycle. The optimal interval of detection then can be obtained by minimizing life cycle cost per unit time using the proposed model.