Two sided disassembly line balancing problem with rest time of works: A constraint programming model and an improved NSGA II algorithm

In the process of disassembly, it is difficult for workers who have been in working condition for a long time to ensure the high-quality completion of the tasks they undertake, which will lead to the reduction of disassembly profit. Providing workers with longer rest time within a certain range can improve the quality of work and thus increase dismantling profits. In response to the above phenomenon, this study proposes for the first time a two sided disassembly line balancing problem with rest time of works (TDLBP-RTW), aiming to optimize the disassembly profit, number of workstations, number of sub workstations, workload smoothness, and hazard index. In addition, the existing algorithms for solving the disassembly line balance problem often do not consider the distribution of feasible solutions. Their search process for the solution space tree is quite random, leading to serious repeated searches and resulting in a significant waste of search resources. To solve the above problems, this study improves the NSGAII algorithm and designs a multi-objective evolutionary algorithm (NSGAII-FSDRSA) considering feasible solution distribution and real-time search resource allocation. The biggest difference between NSGAII-FSDRSA and traditional methods is that NSGAII-FSDRSA can analyze the distribution of feasible solutions and the allocation of search resources, and allocate more search resources to areas with dense feasible solution distribution and less search resource allocation based on the analysis results. The performance of the proposed algorithm is verified by solving three classical examples and by comparing with many meta-heuristic algorithms. Then apply the proposed model and method to the refrigerator disassembly production line of a disassembly enterprise in China. The disassembly scheme of NSGAⅡ-FSDRSA is superior to five classic multi-objective algorithms. The results indicate that this method can improve the performance of the disassembly line.