Dalian University of Technology
The National Social Science Fund of China(19BGL029); National Defense Basic Research Program(JCKY2019205B012)；Key Program of DUT National Defense Innovation Foundation(DUT18GF108)
In this study, lot-splitting is adopted in the process of Seru production system formation for inter-Seru imbalance problem caused by unreasonable batch size in Seru production. A multi-objective optimization model of line-Seru conversion is developed. The model aims to minimize the total throughput time and the total labor hours, by making joint decisions on Seru formation and lot-splitting in the conversion process. Considering the characteristics of multi-objective optimization problem and the complexity of the solution space, a local search strategy is added to improved the algorithm, the INSGA-II is proposed to solve the problem, and an encoding method based on vernier is designed to express lot-splitting strategy to satisfy the constraint when Seru quantity changes. In evolution, the batch sizes and product types of each Seru are continuously optimized to balance the workload between Serus and shorten total throughput time. Finally, the effectiveness of the method is verified by numerical examples. The results showed that lot-splitting can better balance the workload between Serus when the quantity of product with a high fluctuation.