A Multi-Microgroup Coevolutionary Algorithm for Open Shop Scheduling Problem Considering Preventive Maintenance

This article proposes an open shop scheduling problem considering two types of preventive maintenance: routine maintenance and safety maintenance. A mixed integer scheduling model to minimize the makespan and cost under various resource constraints. To solve this new model, a multi-microgroup coevolutionary grey wolf algorithm (MCGWA) is proposed. In the MCGWA, the whole population is divided into multiple microgroups to search independently for expanding the search range. And a coevolution method is designed for each microgroup learns iteratively. Then, a microgroup exchange strategy is presented to prevent falling into the local optimum earlier. Finally, through extensive experimental validation and statistical analysis, the results show that the proposed multi-microgroup coevolutionary grey wolf algorithm outperforms other comparative algorithms in the open shop scheduling problem considering two types of preventive maintenance in mind. The results of the study can provide decision support to manufacturing companies in the practical development of scheduling and maintenance programmes.