Aiming at improving assembly line efficiency and flexibility, a balancing method of parallel U-shaped assembly line system is proposed. Based on the improved product priority diagram, the bidirectional priority value formula is obtained. Then, assembly lines are partitioned into z-q partitions and workstations are defined. After that, the mathematical model of the parallel U-shaped assembly line balancing problem is established. A heuristic algorithm based on bidirectional priority values is used to solve explanatory examples and test examples. It can be seen from the results and the effect indicators of the assembly line balancing problem that the heuristic algorithm is suitable for large balancing problems. The proposed method has higher calculation accuracy and shorter calculation time. The balancing effect of the parallel U-shaped assembly line is better than that of single U-shaped assembly line, which verifies the superiority of the parallel U-type assembly line and effectiveness of the proposed method. It provides a theoretical and practical reference for parallel U-type assembly line balancing problem.

为提高流水线效率和灵活性，提出了一种平行U型流水线系统的平衡方法。基于改进后的产品优先级图，得到双向优先级值公式。然后，装配线被划分为zq定义了分区和工作站。进而建立了平行U型流水线平衡问题的数学模型。基于双向优先级值的启发式算法用于求解解释性示例和测试示例。从流水线平衡问题的结果和效果指标可以看出，启发式算法适用于大型平衡问题。该方法具有较高的计算精度和较短的计算时间。平行U型流水线的平衡效果优于单U型流水线，验证了平行U型流水线的优越性和所提方法的有效性。为平行U型流水线平衡问题提供了理论和实践参考。