Balancing mixed-model multi-maned assembly line with unpaced synchronous transfer

Mixed-model multi-manned assembly lines with unpaced synchronous transfer are common in industrial practice, while they have been overlooked by existing research on assembly line balancing problem. This article attempts to model and solve mixed-model multi-manned assembly line balancing problem with unpaced synchronous transfer. Firstly, a mixed integer linear programming mathematical model is established for the problem, with the primary objective of optimizing the cycle time and the secondary objective of optimizing the total number of workers. Then, a genetic algorithm is proposed due to the NP-hard nature of the problem. In proposed algorithm, a dynamic lower bounding method is specifically designed to address the challenges posed by unpaced synchronous transfer. Finally, experimental research demonstrates the effectiveness of the proposed algorithm. The experimental results show that, the proposed algorithm can achieve effective results in solving small-sized problems through precise model solutions as a control, and can exhibit the good performance when comparing with several common algorithms. Additionally, evaluation experiments have also shown that the dynamic lower bound method is suitable for solving design.