Remaining useful life estimation for repairable multi-state components subjected to multiple maintenance actions

Highlights: • Estimated the availability of components with universal generating function. • Developed model for component availability using failure and maintenance rates. • Estimated the expected future assets integrity via maintenance actions. • Predicted availability by considering – no, minor and major maintenance actions. -- Abstract: This paper discusses the methodologies for determining the reliability and remaining useful life (RUL) of repairable Multi-State Components (MSCs) subjected to different maintenance actions. By utilizing the degradation rates of the components that depend on the failure and maintenance rates, the transition intensities at the performance states and the Universal Generating Function (UGF), the availability and Mean Time To failure (MTTF) was obtained. The technique developed in this study is used to determine the expected RUL of a Feed Water System (FWS) of a power generating plant that uses three maintenance policies that include – no, minor and major maintenance actions for the components integrity management. The study also shows the influence of repeated maintenance actions on the RUL of the components and the impact on reliability at the lifecycle durations of the components and systems.