Maintenance Risk Based Inspection Optimization Model in Multi-Component Repaiable System with Economic Failure Interaction

Inspection is one of the important activities to detect and fix failures in repairable system. Optimization of inspection intervals decreases expected costs of maintenance system, reduces inspection costs and increases the performance of operating system. This paper proposes a new model to reliability and cost evaluation and figure out the optimal periodic inspection interval on a finite time horizon. In addition, the grouping maintenance preferred to individual maintenance as economic failure dependency. The costs are include inspection, repair, and downtime. The downtime cost is proportional to the elapsed time from failure time to its detection at next inspection time. On a finite time horizon, the objective of current study is to figure out the optimal inspection interval for the soft failure component to minimize the expected total cost. In addition, the expert judgment is used to considering risk in inspection. Therefore, a sample problem is solved and numerical results are presented. Result indicates, the risk reduces inspection interval time.