A novel modeling framework for a degrading system subject to hierarchical inspection and maintenance policy

• Published in: Applied mathematical modelling Vol. 120; pp. 636 - 650
• Main Authors: Zhang, Aibo, Liu, Xingheng, Wu, Zhiying, Xie, Min
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.08.2023
• Subjects: Condition-based maintenance; Hidden failures; Hierarchical model; Maintenance optimization; Partial and full inspection; Unrecoverable degradation; Hierarchical model; Maintenance optimization; Condition-based maintenance; Hidden failures; Partial and full inspection; Unrecoverable degradation
• ISSN: 0307-904X
• DOI: 10.1016/j.apm.2023.04.009

•Proposing a generalized hierarchical inspection and maintenance policy for systems with partial and full inspections.•Incorporating the collected system information (e.g., functional or not, degradation level) into system performance assessment.•Building an analytical cost model for the generalized hierarchical maintenance model. Most engineering systems exhibit degrading performance in their designated service times as influenced by their working conditions. Thus, inspection and maintenance actions are crucial for maintaining their performance. Among these, critical engineering systems, such as compressors and safety valves, are typically subject to a multi-level inspection scheme consisting of partial and full inspections. In this study, inspired by this inspection scheme, we propose a hierarchical maintenance model to incorporate collected system performance information from these inspection interventions. Partial inspections verify whether the system is functional or not, and then partial preventive maintenance is performed; a more accurate system state is known at the instant of full inspections, which serve as windows for the conduction of condition-based maintenance. The proposed maintenance policy is then applied to a system undergoing monotone stochastic degradation. Subsequently, the average cost per unit time in the operational phase and the sensitivity analysis with respect to variables, such as the preventive maintenance threshold, inspection intervals, and the maintenance effect factors, are investigated. Theoretical results and numerical examples are obtained to examine the applicability of the generalized model.