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，以适应中断。当公司提前警告可能发生中断或中断的可能性和持续时间发生变化时，一组模型将规定应对中断的最佳策略。另一组模型将研究面临中断的公司可用的替代战略，包括双重采购、紧急采购、需求管理和能力灵活性。这些模型将使用经典库存理论和马尔可夫决策过程来制定和求解。此外，本研究将研究多层次供应链中中断的级联效应。通过模拟和优化技术的结合，该研究将确定这种系统的漏洞，并制定在系统内放置安全库存的策略，以缓冲中断。开发的许多模型将集成到一个免费分发的软件包中，该软件包模拟多级库存系统，可用于研究和课堂设置。如果成功，这项研究将产生一套变革性的模型，用于供应链设计和管理，在计划阶段处理风险，而不是在操作阶段。它的目的是改变规划者对供应链“最优性”的看法，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，从长远来看，未能考虑到这种中断的政策可能会付出极其高昂的代价。初步结果表明，无需对基础设施或库存进行大量投资，供应链就可以大大增强对中断的抵御能力。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的规划者有用。

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.