A Condition-based Maintenance Policy for Two-stage Continuous Degradation Considering Inspection Errors

Inspection is susceptible to human error and limitations stemming from equipment and methodology, resulting in imperfect outcome. Additionally, the maintenance decision-making regarding to two-stage continuous degradation lacks the consideration of two inspection errors, i.e., false positive (FP) and false negative (FN). Motivated by filling the gaps, this paper introduces a condition-based maintenance strategy for two-stage continuous system, which is executed in conjunction with the outcome of imperfect inspection and the deterioration magnitude. Specifically, if the degradation value of the normal stage exceeds the pre-set threshold, a threshold-based replacement will be implemented; and the system suffers replacement simultaneously once the defective state is diagnosed. The long run cost rate, serving as the criterion, has been minimized via optimizing the inspection interval and replacement limit. Again, a numerical maintenance planning experiment of high-speed railway bearing has been conducted to verify the superiority of the cost-saving and robustness subordinate to the proposed maintenance policy.