A suitable inspection policy definition for system with two modes of degradation
Abstract
In this paper, a condition-based maintenance policy is proposed for a gradually deteriorating system with several modes of deterioration. The gamma process is used to describe the system degradation. The system deteriorates from a good as new state to the break down state (when the aging variable reaches a failure level). The level of deterioration can only be known by inspections and the time of change of degradation mode is not detected on line. The aim of the policy is to propose a suitable inspection schedule in every mode of deterioration as well as a related maintenance decision rule. A preventive maintenance is planned when the predicted deterioration level at the next inspection overpasses the failure level with a probability greater than a limit value.