Degradation Modelling and Predictive Opportunistic Maintenance for Two-Unit Systems with an Intermittent Operation Component Considering Degradation Interaction

In this paper, an opportunistic predictive maintenance is developed for a system composed one continuous operation component (COC) and one intermittent operation component (IOC). The COC continuously operates in consistent with the system. In contrast, the IOC alternatively works in operation and standby modes. The degradation of the COC could result in increasing working frequency of the IOC, which could accelerate the degradation process of the IOC. Omitting this degradation interaction in degradation modeling and reliability assessment could results in inaccuracy lifetime prognostic and suboptimal maintenance plan. Therefore, in this work, a degradation model for the IOC is proposed considering the influence of the COC’s degradation state. Reliability model of the IOC is then derived, which is used for predictive maintenance. Based on the proposed degradation models an opportunistic predictive maintenance policy is proposed, considering also structural and economic dependencies between components. Finally, a case study on an air compressor system is conducted to show the viability and benefits of the proposed models