Models and approaches for large scale supply chain planning

供应链就是为了顺畅地管理产品需求而进行的协作。随着产品(以及合作伙伴)数量的增加，供应链规划变得复杂起来。计划的大部分困难来自需求和供应的不确定因素。为了顺利管理供应链，一种选择是限制产品数量，但企业提供一系列产品来满足大量客户的需求。在这种情况下，为了保持供应链的精益，产品的设计方式是大多数最终产品共享几个共同的或经济上可替代的组件/中间产品和工艺。有两个极端：为每个产品设计特定于产品的组件；以及设计可以适合每个产品的单个通用组件。这两种选择都有一定的优缺点，为了平衡两者的优缺点，最终产品被分成不同的类别，每个类别共享可替代的组件。例如，特定宽度的纸卷可用于生产多种不同宽度的最终产品。 确定类别的数量和将产品分类是非常复杂的问题。在数学术语中，这个问题被称为集合划分问题，而在实践中它被称为分类问题。在供应链中，我们在不同阶段(仓库、采购、零售、运输等)遇到许多分类类型的问题。由于这些问题的组合和非线性性质，需要有效的求解方法。在本研究中，我们的第一步是对相关文献进行系统的回顾，丰富现有的知识。我们发现与供应链相关的分类问题很少，在第二步，我们将开发基于数学模型的方法和理论来解决这些问题。根据问题的复杂性、问题的大小和使用情况，我们将开发和测试方法的组合。第三，将通过出版物和研讨会传播最有效和最适当的办法。特别是，我们的重点是： 1)制定和测试在这些情况下更适合供应链的策略。 2)发展数学规划求解方法，有效地解决这类复杂模型的求解问题。 3)开发/探索作为性能基准的测试用例。 这项研究的结果将是一套可供研究人员和实践者使用的方法和规划工具。这项研究的其他成果包括几名在这一研究领域接受过培训的高素质专业人员。

Supply chain is all about collaboration for managing the product demand smoothly. The supply chain planning becomes complex as the number of products (and thus partners) grows. Most of the difficulty in planning arises from the uncertainties in demand and supply. To manage the supply chain smoothly, one option is to limit the number of products but businesses offer a portfolio of products to cater a large pool of customers. In this situation, to keep the supply chain lean, products are designed in such a way that most of the final products share several common or economically substitutable components / intermediate products and processes. There are two extremes: Designing the product specific component for each product; and designing a single universal component that can fit in every product. Both options come with certain advantages and disadvantages and to balance the advantages and disadvantages associated with the both, final products are segregated into different categories with each category sharing substitutable components. For instance, a paper roll of a specific width can be used to produce multiple final products of varied width. Determining the number of categories and classification of products into categories are very complex problems. In mathematical terms, the problem is known as set partition problem and in practice it is called assortment problem. In supply chains we encounter numerous assortment type problems at various stages (warehouse, sourcing, retail, transportation, etc.). Due to combinatorial and nonlinear nature of these problems efficient solution approaches are required. In this research, our first step is to do systematic review of the relevant literature and enrich the existing knowledge. We have identified few assortment problems associated with supply chains and in the second step we will develop mathematical modeling based approaches and theory to solve such problems. Based on the problem complexity, problem size and usage we will develop and test combination of approaches. Thirdly, the most effective and suitable approaches will be disseminated through publications and seminars. In particular, our key focus is to: 1) Develop and test strategies which are more suitable for supply chains under these circumstances. 2) Develop mathematical programming solution approaches which are effective and efficient in solving such complex models. 3) Develop /explore test cases for bench-marking the performance. The outcome of this research will be a set of methodologies and planning tools that could be used by researchers as well as practitioner. Other outcomes of the research include several highly qualified professionals trained in this area of research.