作者：Yaping Li, Tangbin Xia, Zhen Chen, Ershun Pan

题名：Multiple degradation-driven preventive maintenance policy for serial-parallel multi-station manufacturing systems 

期刊：Reliability Engineering & System Safety (online:2022.10)

摘要：Machine reliability degradation is common in production systems; besides, machine production rate (PR) degradation also widely occurs as the systems deteriorate. The PR has an essential impact on the capacity of the systems. However, the few efforts involving the capacity requirements in preventive maintenance (PM) policies have not yet taken PR degradation into account, assuming all the PRs are constant. It is necessary for PM policies to consider the dynamic capacity caused by the deteriorating PR. With the two types of degradation involved, a multiple degradation-driven preventive maintenance (MDPM) policy for the serial-parallel multi-station manufacturing systems (SMMS) is proposed. Since PM has an impact on PR each time it is executed, an evolution model of PR, with the imperfect maintenance effect considered, is developed. The capacity efficiency based on deteriorating PR is put forward. By maximizing capacity efficiency and minimizing cost rate, a station-level PM optimization model is proposed. Then, the process of the MDPM scheduling is formulated, where three rules, including minimum remaining time, maintenance time window and capacity balance, are suggested for the system-level decision. Finally, the case study is illustrated to show the application of the PR evolution model and the advantages of the proposed MDPM policy.