Modeling and Mitigating Supply Chain Vulnerabilities

该研究项目将开发和解决设计和运营供应链的模型，这些供应链对中断具有弹性。 一组模型将规定最佳的战略，以应付中断时，公司有提前警告，中断可能发生或中断的概率和持续时间已经发生了变化。 另一组模型将研究面临中断的公司可用的替代策略，包括双重采购，紧急采购，需求管理和能力灵活性。 这些模型将制定和解决使用经典的库存理论和马尔可夫决策过程。 此外，本研究亦将探讨多阶层供应链中中断事件的连锁效应。 使用模拟和优化技术相结合，研究将确定这样一个系统的漏洞，并制定战略，将安全库存库存系统内的缓冲，以防止中断。 许多开发的模型将被集成到一个免费分发的软件包，模拟多级库存系统，并可能在研究和课堂设置中使用，如果成功，这项研究将产生一个变革性的供应链设计和管理模型，在规划阶段处理风险，而不是操作。 它旨在通过证明许多问题的最优解决方案在中断的情况下根本不是最优的，并且从长远来看，未能考虑这种中断的政策可能会付出极其高昂的代价，从而改变规划者对供应链中“最优性”的思考方式。 初步结果表明，供应链可以在不对基础设施或库存进行大量投资的情况下，显著提高对中断的抵御能力。 这项研究的模型和见解将对工业环境中的规划者以及救灾机构和军队等非商业企业有用。

This research project will develop and solve models for designing and operating supply chains that are resilient to disruptions. One set of models will prescribe optimal strategies for coping with disruptions when the firm has advanced warning that a disruption may occur or that the probability and duration of a disruption has changed. Another set of models will examine alternate strategies available to firms facing disruptions, including dual sourcing, emergency sourcing, demand management, and capacity flexibility. These models will be formulated and solved using classical inventory theory and Markov decision processes. In addition, this research will study the cascading effect of disruptions in a multi-echelon supply chain. Using a combination of simulation and optimization techniques, the research will identify the vulnerabilities of such a system and develop strategies for placing safety stock inventory within the system to buffer against disruptions. Many of the models developed will be integrated into a freely distributed software package that simulates a multi-echelon inventory system and may be used in both research and classroom settings.If successful, this research will produce a transformative set of models for supply chain design and management that handle risk during the planning stage, rather than the operational one. It aims to transform the way planners think about "optimality" in supply chains by demonstrating that optimal solutions to many problems are not optimal at all in light of disruptions, and that a policy that fails to account for such disruptions can be extremely costly in the long run. Preliminary results suggest that supply chains can be made significantly more resilient to disruptions without large investments in infrastructure or inventory. The models and insights from this research will be useful to planners in industrial settings as well as non-commercial enterprises such as disaster relief agencies and the military.