Critical national infrastructure reliability modeling and analysis

One of the top 10 priorities of the U.S. Department of Homeland Security is protection of our critical national infrastructures including power, communications, transportation, and water. This paper presents models to quantify the interdependencies of critical infrastructures in the U.S. and evaluate plans to compensate for vulnerabilities. Communications is a key infrastructure, central to all others, so that understanding and modeling the risk due to communications disruptions is a high priority in order to enhance public safety and infrastructure resiliency. This paper discusses reliability modeling and analysis at a higher level than usual. Reliability analysis typically deals at the component or sub-system level and talks about “mean time to failure” and “mean time to repair” to derive availability estimates of equipment. Here, we deal with aggregate scales of failures, restoration, and mitigation across national infrastructures. This aggregate scale is useful when examining multiple infrastructures simultaneously with their interdependencies. System dynamics simulation models have been created for both communication networks and for the infrastructure interaction models that quantify these interactions using a risk-informed decision process for the evaluation of alternate protective measures and investment strategies in support of critical infrastructure protection. We will describe an example development of these coupled infrastructure consequence models and their application to the analysis of a power disruption and its cascading effect on the telecommunications infrastructure as well as the emergency services infrastructure. The results show significant impacts across infrastructures that can become increasingly exacerbated if the consumer population moves more and more to telecom services without power lifeline.