Rabbit chase (RC) is used as one of the most effective techniques in manufacturing systems, as such systems have high level of adaptability and increased productivity in addition to providing uniform workload balancing and skill improving environment. In assembly systems, RC inspires the development of walking worker assembly line (WWAL). On the other hand, U-type assembly lines (UALs) may provide higher worker utilization, lower space requirement and more convenient internal logistics when compared to straight assembly lines. In this context, this study aims to improve assembly line performance by generating RC cycles on WWAL with respect to task assignment characteristics of UAL within reasonable walking distance and space requirement. Therefore, a novel line configuration, namely, segmented rabbit chase-oriented U-type assembly line (SRCUAL), emerges.,The mathematical programming approach treats SRCUAL balancing problem in a hierarchical manner to decrease computational burden. Firstly, segments are generated via the first linear programming model in the solution approach for balancing SRCUALs to minimize total number of workers. Then, stations are determined within each segment for forward and backward sections separately using two different pre-emptive goal programming models. Moreover, three heuristics are developed to provide solution quality with computational efficiency.,The proposed mathematical programming approach is applied to the light-emitting diode (LED) luminaire assembly section of a manufacturing company. The adaptation of SRCUAL decreased the number of workers by 15.4% and the space requirement by 17.7% for LED luminaire assembly system when compared to UAL. Moreover, satisfactory results for the proposed heuristics were obtained in terms of deviation from lower bound, especially for SRCUAL heuristics I and II. Moreover, the results indicate that the integration of RC not only decreased the number of workers in 40.28% (29 instances) of test problems in U-lines, but also yielded less number of buffer points (48.48%) with lower workload deviation (75%) among workers in terms of coefficient of variation.,This study provides convenience for capacity management (assessing capacity and adjusting capacity by changing the number of workers) for industrial SRCUAL applications. Meanwhile, SRCUAL applications give the opportunity to increase the capacity for a product or transfer the saved capacity to the assembly of other products. As it is possible to provide one-piece flow with equal workloads via walking workers, SRCUAL has the potential for quick realization of defects and better lead time performance.,To the best of the authors’ knowledge, forward–backward task assignments in U-type lines have not been adapted to WWALs. Moreover, as workers travel overall the line in WWALs, walking time increases drastically. Addressing this research gap and limitation, the main innovative aspect of this study can be considered as the proposal of a new line design (i.e. SRCUAL) which is sourced from the hybridization of UALs and WWAL as well as the segmentation of the line with RC cycles. The superiority of SRCUAL over WWAL and UAL was also discussed. Moreover, operating systematic for SRCUAL was devised. As for methodical aspect, this study is the first attempt to solve the balancing problem for SRCUAL design.

中文翻译：

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面向分段追兔的U型流水线设计优化新方法：以照明行业为例

兔子追逐 (RC) 被用作制造系统中最有效的技术之一，因为此类系统除了提供统一的工作负载平衡和技能改进环境外，还具有高度的适应性和更高的生产力。在装配系统中，RC 激发了步行工人装配线 (WWAL) 的发展。另一方面，与直线装配线相比，U 型装配线 (UAL) 可以提供更高的工人利用率、更低的空间需求和更方便的内部物流。在这种情况下，本研究旨在通过在 WWAL 上根据 UAL 的任务分配特征在合理的步行距离和空间要求内生成 RC 循环来提高装配线性能。因此，一种新颖的生产线配置，即分段追兔型U型流水线（SRCUAL），，数学规划方法以分层方式处理 SRCUAL 平衡问题，以减少计算负担。首先，通过平衡 SRCUAL 以最小化工人总数的解决方案方法中的第一个线性规划模型生成段。然后，使用两个不同的抢占式目标编程模型分别确定每个段内的前向和后向段的站点。此外，开发了三种启发式方法以提供具有计算效率的解决方案质量。所提出的数学规划方法应用于制造公司的发光二极管 (LED) 灯具组装部分。与 UAL 相比，SRCUAL 的适应性使 LED 灯具组装系统的工人数量减少了 15.4%，空间需求减少了 17.7%。而且，在偏离下限方面，特别是对于 SRCUAL 启发式 I 和 II，获得了所提出的启发式的令人满意的结果。此外，结果表明，RC 的集成不仅减少了 U 线测试问题中 40.28%（29 个实例）的工人数量，而且产生了更少的缓冲点（48.48%）和更低的工作量偏差（75 %) 工人之间的变异系数。,本研究为工业 SRCUAL 应用的容量管理（通过改变工人数量评估容量和调整容量）提供了便利。同时，SRCUAL 应用程序提供了增加产品产能或将节省的产能转移到其他产品组装的机会。由于可以通过步行工人提供具有相同工作量的一件式流程，SRCUAL 具有快速实现缺陷和更好的交货时间性能的潜力。据作者所知，U 型生产线中的前向-后向任务分配尚未适应 WWAL。此外，随着工人在 WWAL 中整体行走，步行时间急剧增加。针对这一研究差距和局限性，本研究的主要创新方面可以被认为是一种新的线路设计（即 SRCUAL）的提议，该线路设计源自 UAL 和 WWAL 的杂交以及线路与 RC 循环的分割. 还讨论了 SRCUAL 优于 WWAL 和 UAL。此外，还设计了 SRCUAL 的操作系统。在方法方面，本研究首次尝试解决 SRCUAL 设计的平衡问题。