Abstract In this paper we present a novel transshipment problem for a large apparel retailer that operates an extensive retail network. Our problem is inspired by the logistics operations of a very large fast fashion retailer in Turkey, LC Waikiki, with over 475 retail branches and thousands of products. The purpose of transshipments is to rebalance stocks across the retail network to better match supply with demand. We formulate this problem as a large mixed integer linear program and develop a Lagrangian relaxation with a primal–dual approach to find upper bounds and a simulated annealing based metaheuristic to find promising solutions, both of which have proven to be quite effective. While our metaheuristic does not always produce better solutions than a commercial optimizer, it has consistently produced solutions with optimality gaps lower than 7% while the commercial optimizer may produce very poor solutions with optimality gaps as high as almost 300%. We have also conducted a set of numerical experiments to uncover implications of various operational practices of LC Waikiki on its system’s performance and important managerial insights.

中文翻译：

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容量约束下快时尚零售商转运问题的确定性模型

摘要在本文中，我们为经营广泛零售网络的大型服装零售商提出了一个新的转运问题。我们的问题受到土耳其一家大型快时尚零售商 LC Waikiki 的物流运营的启发，该零售商拥有超过 475 个零售分支机构和数千种产品。转运的目的是重新平衡整个零售网络的库存，以更好地匹配供需。我们将这个问题表述为一个大型混合整数线性规划，并使用原始-对偶方法开发拉格朗日松弛以找到上限，并使用基于模拟退火的元启发式方法来寻找有希望的解决方案，这两种方法都已被证明非常有效。虽然我们的元启发式并不总是比商业优化器产生更好的解决方案，它始终生成最优差距低于 7% 的解决方案，而商业优化器可能会产生最优差距高达近 300% 的非常差的解决方案。我们还进行了一组数值实验，以揭示 LC Waikiki 的各种运营实践对其系统性能和重要管理见解的影响。