Integrating flexible preventive maintenance activities into two-stage assembly flow shop scheduling with multiple assembly machines

In this paper, preventive maintenance (PM) activities are incorporated into two-stage assembly flow shop scheduling where m1 dedicated machines in fabrication stage and m2 machines in assembly stage. Each machine is given a new feature maintenance level, whose initial value is determined based on the Weibull probability distribution. To ensure the machines' reliability and production continuity, we need to find a fit product sequence along with PM execution time points. Hence this paper tries to tackle this new integration problem by a mixed integer linear programming model, two heuristics MCMTPM and NEHPM, and a PM-based iterated greedy algorithm (IGPM). IGPM is embedded with a problem-specific solution evaluation and two types of local search methods. The final experimental results show that compared with the other 9 state-of-the-art methods, the proposed IGPM embedded with NEHPM and reference local search generates the best results in all benchmark instances.