Joint Optimization of Integrated Mixed Maintenance and Distributed Two-Stage Hybrid Flow-Shop Production for Multi-Site Maintenance Requirements

•A new maintenance mode with worker-mixed is introduced.•An model integrating production, operation and maintenance is established.•An improved genetic algorithm (INSGA-II) is designed.•The advantages of the new mixed service model are confirmed by experiments.•Elaborate tests are conducted to verify the performance of the INSGA-II.