Logistics and Transportation in Supply Chains

供应链中的物流与运输

• 批准号: RGPIN-2014-04277
• 负责人: Bookbinder, James
• 金额: $ 1.6万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=636833
• 关键词: Logistics; Transportation; Supply; Chains

SHIPMENT CONSOLIDATION (SCL) is the purposeful combination of several small loads, for dispatch together, as a single larger shipment. Although delay of order deliveries may incur a cost, SCL can lead to significant economies of scale in transportation, thus reducing the overall system cost. Service to the receiver of the goods need not be degraded, if attention is paid to the maximum holding time (length of the consolidation cycle). The shipper wishes to select an appropriate consolidation policy that determines the right moment to terminate the accumulation process and dispatch a load. Our new work aims to propose and study policies that are more general than the typical ones that are based solely upon the aggregate shipment weight and/or the maximum holding time. Our new models are capable of recording more information about the order-accumulation process (e.g. delays of individual orders), thus permitting consideration of policies dependent on such information. We will also improve the accuracy of our models by considering Markovian arrival processes that go beyond the typically-assumed Poisson distribution, and by incorporating potential correlations between the arrivals of consecutive orders and their weights. Continuing our recent success with the Matrix-Analytic method, we will develop efficient solution techniques to obtain accurate results. We will employ a more realistic cost structure: a delay penalty cost (customer disutility of waiting) that is strictly increasing in that waiting time. The ultimate goals are to identify the form of the optimal policy for the general case, and to construct efficient algorithms to determine the parameters of that optimal policy, for a consolidation process involving orders of multiple products whose transport costs and/or delay-penalty rates may differ.LOT-SIZING PROBLEMS seek to determine the timing and replenishment quantities, of a single item or of several items, to minimize total costs while meeting demand requirements. Demand, based on orders from customers, can be satisfied through the production and distribution when those items are grouped into families. The joint coordination via families recognizes the sharing of a resource in transportation (as in SCL) or in the manufacturing portion of the supply chain. Our research in the study of lot-sizing of several multi-product families is new in the production context. This work will also shed light on coordinated inventory control of products ordered from a common supplier. We will explore various strong reformulations for the multi-family lot-sizing problem, and test new heuristics to speed up solution times, maintaining solution quality. THE INVENTORY-ROUTING PROBLEM concerns both vehicle routing (the sequencing of customers in making deliveries by truck) and the management by the vendor of stocks for those customers whose products are being delivered. Our research allows, when advantageous, the development of indirect routes. These serve logically-grouped sets of customers that receive goods through a given cross-dock (CD). There can be as many customers on the routes as permitted by vehicle capacity. Both the inventory holding costs at customers and the pipeline stocks are considered. This theme extends, in a non-trivial way, the applicant’s previous publications on VMI (Vendor Managed Inventory) and cross-docking. We hope to obtain general, provably near-optimal results, and an efficient solution algorithm, for a system containing several CDs in which distinct products from multiple suppliers are delivered by a private fleet on routes to various customers. This work will represent one of the very first such models.

集运（SCL）是将几个小的货物有目的地组合在一起，作为一个较大的货物发送。虽然延迟交付订单可能会产生成本，但SCL可以带来显著的运输规模经济，从而降低整体系统成本。如果注意最长保存时间（合并周期的长度），对货物接收者的服务不必降低。托运人希望选择一个适当的整合政策，确定正确的时间来终止积累过程和调度负载。我们的新工作旨在提出和研究比仅基于总装运重量和/或最大保持时间的典型政策更一般的政策。我们的新模型能够记录有关订单累积过程的更多信息（例如单个订单的延迟），从而允许考虑依赖于这些信息的政策。我们还将通过考虑超越通常假设的泊松分布的马尔可夫到达过程，并通过将连续订单的到达与其权重之间的潜在相关性，来提高模型的准确性。继续我们最近的成功与矩阵分析方法，我们将开发有效的解决方案技术，以获得准确的结果。我们将采用一个更现实的成本结构：延迟惩罚成本（客户等待的负效用），在等待时间内严格增加。最终的目标是确定一般情况下的最优策略的形式，并构造有效的算法来确定最优策略的参数，对于一个包含多个产品订单的合并过程，其运输成本和/或延迟惩罚率可能不同。批量问题寻求确定单个产品或多个产品的时间安排和补货数量，在满足需求的同时，最大限度地降低总成本。基于客户订单的需求，可以通过将这些产品分组到系列中的生产和分配来满足。通过家庭的联合协调承认在运输（如SCL）或供应链的制造部分中的资源共享。我们的研究中的批量的几个多产品系列的研究是新的生产背景下。这项工作也将阐明从一个共同的供应商订购的产品的协调库存控制。我们将探索多系列批量问题的各种强重构，并测试新的算法以加快解决时间，保持解决方案的质量。运输路线问题既涉及车辆路线（客户用卡车送货的顺序），也涉及供应商对那些要送货的客户的库存管理。我们的研究允许在有利的情况下开发间接路线。这些服务于通过给定的交叉码头（CD）接收货物的逻辑分组的客户集。在车辆容量允许的情况下，路线上可以有尽可能多的客户。考虑了客户的库存持有成本和管道库存。这个主题扩展，在一个不平凡的方式，申请人以前的出版物上的VMI（供应商管理库存）和交叉对接。我们希望获得一般的，可证明接近最优的结果，和一个有效的解决方案算法，包含几个CD的系统中，不同的产品从多个供应商提供的私人车队的路线上，以各种客户。这项工作将代表第一个这样的模型之一。