Optimal Supply Diversification Under General Supply Risks
Optimal Supply Diversification Under General Supply Risks
复制标题
DOI：
10.1287/opre.1080.0667
复制
发表时间：
2009-11
期刊：
影响因子：
--
通讯作者：
A. Federgruen;N. Yang
中科院分区：
文献类型：
--
作者：
A. Federgruen;N. Yang
我们分析了一个公司或公共组织的规划模型，需要通过从多个来源采购供应来满足给定项目的不确定需求。雇用多个供应商的必要性源于这样一个事实，即当向任何一个供应商下订单时，只有订单大小的随机部分可用。该模型考虑了一个单一的需求季节与给定的需求分布，其中所有的供应需要在季节开始前同时订购。供应商在产量分布、采购成本和产能水平方面各不相同。该计划模型确定哪些潜在供应商将被保留，以及向每个供应商下多大的订单。我们考虑两个版本的规划模型：在第一，服务约束模型（SCM），订单必须是这样的，可用单位的可用供应覆盖随机需求的季节（至少）一个给定的概率。在模型的第二个版本中，总成本模型（TCM），确定订单，以最小化采购成本和季末库存和短缺成本的总和。在具有单个完全可靠供应商的经典库存模型中，已知这两个模型是等效的，但在产量不可靠的多个供应商的情况下，等效性会崩溃。对于服务约束和总成本模型，我们开发了一个高效的程序，生成最优的供应商以及最优的订单分配给每个。最重要的是，这些程序产生了各种重要的定性见解，例如，关于哪些供应商允许一个可行的解决方案，当他们有足够的供应和当他们的能力，以及各种模型参数如何影响选定的供应商，总订单规模和最佳成本值。
We analyze a planning model for a firm or public organization that needs to cover uncertain demand for a given item by procuring supplies from multiple sources. The necessity to employ multiple suppliers arises from the fact that when an order is placed with any of the suppliers, only a random fraction of the order size is usable. The model considers a single demand season with a given demand distribution, where all supplies need to be ordered simultaneously before the start of the season. The suppliers differ from one another in terms of their yield distributions, their procurement costs, and capacity levels. The planning model determines which of the potential suppliers are to be retained and what size order is to be placed with each. We consider two versions of the planning model: in the first, the service constraint model (SCM), the orders must be such that the available supply of usable units covers the random demand during the season with (at least) a given probability. In the second version of the model, the total cost model (TCM), the orders are determined so as to minimize the aggregate of procurement costs and end-of-the-season inventory and shortage costs. In the classical inventory model with a single, fully reliable supplier, these two models are known to be equivalent, but the equivalency breaks down under multiple suppliers with unreliable yields. For both the service constraint and total cost models, we develop a highly efficient procedure that generates the optimal set of suppliers as well as the optimal orders to be assigned to each. Most importantly, these procedures generate a variety of important qualitative insights, for example, regarding which sets of suppliers allow for a feasible solution, both when they have ample supply and when they are capacitated, and how various model parameters influence the selected set of suppliers, the aggregate order size, and the optimal cost values.