Design and protection strategies for critical infrastructure systems and supply chains

基础设施系统和供应链是社会功能的基础，并涉及现代生活的方方面面。这些重要系统的例子包括货物和服务分配网络、紧急服务、金融服务、运输和电信网络、电网和供水系统等。不幸的是，最近的世界事件表明，即使是最强大的供应链或基础设施系统也极易受到意外事件的影响。2001年的世界贸易中心恐怖袭击，2004年12月的海啸，以及2005年袭击美国墨西哥湾沿岸的卡特里娜飓风和丽塔飓风，只是我们的关键基础设施不稳定和易受自然灾害和恐怖袭击的最引人注目的证据。其他灾难性较小但更频繁的事件，如工厂火灾、工业事故、罢工和停电，也可能产生昂贵的，有时是有害的影响，特别是如果失去能力或被摧毁的供应线提供基本服务或商品（例如，鉴于所有这些风险和危害，过去几年来，人们对加强可能受到潜在外部干扰的基础设施和供应系统的安全和可靠性的认识和关切有所提高。针对可能的破坏性自然行为或恐怖主义行为进行规划是一项巨大的财政和后勤挑战，特别是考虑到当今后勤系统的规模和复杂性、众多系统要素之间日益相互依赖、各种威胁和危险以及确保大量系统部件安全所涉及的高昂成本。由于一般不可能确保所有资产的安全，因此必须制定系统的办法，以查明关键要素，优化对关键系统部件的保护，甚至建立内在强大的新系统。在过去的几年里，已经开发了一些优化模型，用于确定在中断方面可靠且在基础设施投资方面具有经济成本效益的供应链配置（设计模型）。此外，最近已经提出了新的模型，可以用来提高可靠性的基础设施系统，已经到位，一个完整的重新配置将过于昂贵（保护模型）。本项目的总体目标是开发一套新的优化模型，在这两个可靠性相关的研究领域。特别是，新的建模方法将被开发，以克服一些过于简化的假设，现有的模型的特点，捕捉系统可靠性规划中出现的额外的复杂问题，并反映可能的应用设置的多样性。作为一个例子，未来的建模工作应旨在纳入以下问题的各种组合：（1）系统的不同操作协议（基于成本的供应模式与基于标准的供应模式）;（2）不同类型的危害（自然灾害的预期模型与预谋攻击的最坏情况模型）;（3）不同的基本模型（设施位置、网络、多级供应模型）;（4）随机方面，如可能损失的随机数和特定组件的故障概率;（五）设施保护程度不同（受保护的组件可能完全不受攻击和故障的影响，被中断的可能性较低，或者根据保护投资的水平保留其部分操作能力）;（6）多目标（运营成本、销售损失成本、系统效率、覆盖范围、风险水平）。精确和启发式技术也将被开发来解决新提出的模型。

Infrastructure systems and supply chains are at the basis of societal functions and reach into every aspect of modern life. Examples of these vital systems include goods and service distribution networks, emergency services, financial services, transportation and telecommunication networks, electrical power grids and water supply systems among others. Unfortunately, recent world events have demonstrated that even the strongest supply chains or infrastructure systems can be extremely vulnerable to unforeseen events. The World Trade Centre terrorist attack in 2001, the Tsunami in December 2004, and hurricanes Katrina and Rita, which hit the US gulf coast in 2005, are only the most dramatic evidence of the precariousness and vulnerability of our critical infrastructure to natural disasters and terrorist attacks. Other less catastrophic but more frequent incidents, such as plant fires, industrial accidents, labor strikes and power outages, can also have costly and, sometimes, harmful implications, especially if the incapacitated or destroyed supply line provides essential services or goods (e.g., hospitals, drugs, vaccines).In view of all these risks and hazards, there has been a heightened awareness and concern over the past few years for increasing the security and reliability of infrastructure and supply systems that may be subject to potential external disruptions. Planning against possible disruptive acts of nature or terrorism is an enormous financial and logistical challenge, especially if one considers the scale and complexity of today's logistic systems, the increasing interdependence among numerous system elements, the variety of threats and hazards, and the prohibitive costs involved in securing large numbers of system components. Since it is generally impossible to secure all assets, it is important to devise systematic approaches for identifying critical elements, optimize the protection of key system components and even build new systems which are inherently robust. Optimization techniques can play a significant role in this respect.Over the last few years, a few optimization models have been developed for identifying supply chain configurations that are both reliable with respect to disruptions and economically cost-effective in terms of infrastructure investment (design models). Additionally, new models have been proposed recently which can be used to improve the reliability of infrastructure systems that are already in place and for which a complete reconfiguration would be too costly (protection models).The overall objective of this project is to develop a suite of new optimization models in both of these reliability-related research areas. In particular, new modeling approaches will be developed to overcome some of the overly simplified assumptions which characterize existing models, to capture additional complex issues arising in systems reliability planning, and to reflect the diversity of possible application settings. As an example, future modeling efforts should aim at incorporating various combinations of the following issues: (1) different operational protocols of the systems (cost-based vs. standards-based supply models); (2) different types of hazards (expected models for natural disasters vs. worst-case models for premeditated attacks); (3) different underlying models (facility location, network, multi-echelon supply models); (4) stochastic aspects such as random numbers of possible losses and component-specific failure probabilities; (5) different degrees of facility protection (protected components may be completely immune to attacks and failures, have a lower probability of being disrupted, or preserve part of their operational capabilities depending on the level of protection investment); (6) multiple objectives (operational costs, lost-sales cost, system efficiency, coverage, risk level). Both exact and heuristic techniques will also be developed to solve the newly proposed models.