Analysis of Facility Systems’ Reliability When Subject to Attack or a Natural Disaster

Critical infrastructure can be defined as those elements which are necessary for lifeline support and safety. They include such systems as communication systems, water and sewer systems, health services facilities, food production/processing/storage systems, transportation systems, drug production/ stockpiles, and incident sensing/detection/control systems. Each of these systems has unique properties that may define specific issues in operation and management in order to provide a consistent and continuing level of operation. A common question today is whether a particular system or component is vulnerable to failure and whether in some cases failure of one system component will lead to a failure of downstream components. For example, the electrical system failure in Ohio led to significant loss of power in many states of the Northeast US in August, 2003. Grubesic, et al. (2003) has called this cascading failure. There are five major problems in managing, operating and designing infrastructure: 1) for existing systems, identify those components that are subject to natural disasters along with their impacts on system operation; 2) for existing systems, identify those components that if chosen by an interdictor, would impact system operations the most; 3) for existing systems, identify those systems components that should be protected against natural or intentional strikes, in order to keep a system operating efficiently; 4) for a new system, design a system so that its operation is as resilient as possible against natural disasters and intentional strikes; and 5) schedule and allocate protection re sources in order to minimize disruptions and impacts on system efficiency due to natural losses or intentional strikes. These five problem areas capture a range of issues associated with keeping a “lifeline” system in operation.