Joint planning of inspection, replacement, and component decommissioning for a series system with non-identically degrading components
研究了串联系统中多个退化部件的检测、退役与更新联合规划，提出一种最小化成本率的策略，在糖厂锅炉换热器案例中比固定间隔检测节省成本，且与基于状态的方法成本相近但更可预测。
In this paper, a system of multiple degrading components in series reliability is considered where the system performance is a monotonically increasing function of the number of working components. By decommissioning failed components, the system is restored to working order, but the performance loss may only be recovered when the entire system is renewed. The failure risks are managed by inspecting components and conducting preventive decommissioning based on the result. Thus, a complete maintenance and inspection policy will specify when and what components to inspect/decommission and when to renew the entire system. A joint inspection, decommissioning, and renewal plan is developed that minimizes the cost rate and this policy is applied to a boiler heat exchanger operating in a sugar mill. The results show that the proposed policy yields significant savings compared to a benchmark fixed-interval inspection policy and is competitive with a sophisticated condition-based approach. Moreover, in contrast to the condition-based benchmark, the proposed policy provides the entire inspection and renewal plan early in the system's life rather than re-planning after each inspection. Thus, the proposed approach is quite practical — it provides additional predictability in direct expenditures compared to the best condition-based policy and has statistically similar total costs.