Preventive maintenance optimization regarding large-scale systems based on the life-cycle cost

摘要

© 2021 Totem Publishers Ltd. All rights reserved.Unit degradation complicates the comprehensive optimization of reliability design and preventive maintenance (PM) policies for large-scale systems considering the life-cycle. Based on the unit failure rate obeying the Weibull distribution, we propose a cost optimization model for large-scale systems under reliability constraints from the life-cycle perspective. In this study, we consider a simple multi-unit preventive joint maintenance policy where units are assessed and fixed only during planned inspections. However, nonlinear optimization becomes increasingly difficult due to the exponential combination growth caused by numerous units. To overcome this challenge, a genetic algorithm (GA) program is adopted to obtain the global optimal solution covering the unit reliability in the design and manufacturing stages and system PM period in the operation stage. Through real-world example analysis, the correctness and effectiveness of the proposed model and algorithm are verified. The relationship among decision variables, such as maintenance improvement factor, unit reliability, and PM period, is examined. The results simplify the reliability design process for system engineers and enrich reliability theory and applications.