Availability model of equipment based on three-levels maintenance system

Targeting at the complex equipment guaranteed by three-levels maintenance institution, on the assume that “after minor repair is as good as old and after middle or overhaul repair is not as good as new”, it presented a switching chart of equipment application and repair condition transformation in a lifecycle by analyzing equipment application and repair flowing procedure. It also established the connection model between maintenance interval period and availability in the lifecycle, and worked out the average availability related to the fixed maintenance interval period and switch rule. Through analyzing an application case, the optimal maintenance interval period that can ensure the availability is maximal was received, and comparing with “after overhaul repair is as good as new”, in which the applicability and sensitivity of the model are proved. This approach can be used for maintenance decision-making.