Availability and maintenance modeling for a two-component system with dependent failures over a finite time horizon

This article studies the availability and optimal maintenance policy for a two-component system with failure interaction over a finite time horizon. Failure of component 1 is soft and can only be detected by inspections. Failure of component 2 is hard and self-announcing. Each hard failure acts as a shock to the first component and increases its hazard rate. Periodic and opportunistic inspections (offered by failures of component 2) are used to reveal the failure of component 1 and followed by replacement decisions. Furthermore, age-based preventive replacement is performed for component 1. Under this maintenance policy, a recursive method is developed to obtain the availability measure of component 1. Furthermore, the total maintenance cost of component 1 over a finite time horizon is analyzed. The objective is to find the optimal maintenance policy for component 1 such that the expected total cost is minimized. A case study on electrical distribution system is provided to validate the effectiveness of the adopted approach.