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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=645795
• 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.

装运拼装 (SCL) 是有目的地组合多个小货物，作为单个较大的货物一起发货。尽管订单交付延迟可能会产生成本，但 SCL 可以带来显着的运输规模经济，从而降低整体系统成本。如果注意最大保留时间（合并周期的长度），则对货物接收者的服务不必降低。托运人希望选择适当的拼箱政策，以确定终止累积过程并调度货物的适当时机。我们的新工作旨在提出和研究比仅基于总装运重量和/或最长持有时间的典型政策更普遍的政策。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出通常假设的泊松分布的马尔可夫到达过程，并结合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。延续我们最近在矩阵分析方法方面取得的成功，我们将开发高效的求解技术以获得准确的结果。我们将采用更现实的成本结构：延迟惩罚成本（客户等待的负效用）在等待时间内严格增加。最终目标是确定一般情况下最佳策略的形式，并构建有效的算法来确定该最佳策略的参数，对于涉及运输成本和/或延误罚款率可能不同的多种产品订单的整合流程。**批量问题寻求确定单个项目或多个项目的时间和补货数量，以在满足需求要求的同时最小化总成本。当这些物品被分组到系列中时，可以通过生产和分配来满足基于客户订单的需求。通过家庭进行的联合协调承认运输（如 SCL）或供应链的制造部分的资源共享。我们对多个多产品系列批量大小的研究在生产环境中是全新的。这项工作还将阐明从共同供应商订购的产品的协调库存控制。我们将探索针对多户批量问题的各种强有力的重新表述，并测试新的启发式方法以加快解决时间，保持解决方案质量。 * *库存路线问题涉及车辆路线（客户用卡车送货的顺序）和供应商对正在交付产品的客户的库存管理。我们的研究允许在有利的情况下开发间接路线。这些服务为通过给定的越库配送 (CD) 接收货物的逻辑分组的客户群提供服务。在车辆容量允许的范围内，路线上可以有尽可能多的乘客。客户的库存持有成本和管道库存都被考虑。该主题以重要的方式扩展了申请人之前关于 VMI（供应商管理库存）和越库配送的出版物。对于包含多个 CD 的系统，我们希望获得通用的、可证明接近最佳的结果和有效的解决算法，其中来自多个供应商的不同产品由私人车队按路线交付给不同的客户。这项工作将代表最早的此类模型之一。