Strategy Optimization of Multi-Component System Opportunity Maintenance for Electric Multiple Units From a Lean Maintenance Perspective

The deterioration characteristics of electric multiple units (EMUs) components can lead to complex and costly maintenance processes. This paper focuses on investigating the influence mechanism of the interaction between operation and maintenance (O&M) activities within the whole life cycle (WLC) of EMUs' components on the maintenance strategy, based on the concept of lean maintenance (LM). A linear relationship is established between operating costs and the equivalent service age to reflect the trend of the component operating conditions dynamically in relation to deterioration level and maintenance activities, and a bi-level imperfect preventive maintenance (BIPM) strategy considering operating cost (OC) is proposed at the component level. At the system level, a multi-level preventive opportunity maintenance (POM) strategy based on the opportunity maintenance mileage window (OMMW) is proposed for the serial system of EMUs to reduce the number of system downtimes and minimize value waste and achieve long-term economic benefits. The experimental results demonstrated that compared to maintenance strategies that do not consider operating costs, this strategy optimizes the total maintenance cost for multi-component systems of EMUs in the long term by implementing more aggressive measures while ensuring component reliability, system availability, and schedule rationality.