Supply-at-Risk: Resilience Metric for Infrastructure Systems: Framework for assessing and comparing resilience of infrastructure systems in urban areas

Urban systems, composed of households, businesses, and infrastructures, are continuously evolving and expanding. This has several implications because the impacts of disruptions, and the complexity and interdependence of systems, are rapidly increasing. Hence, we face a challenge in how to assess resilience of infrastructure systems in these urban areas. This issue has significant impact on infrastructure systems design and development. The aims of this study were to: (1) apply a framework for modeling interdependencies between infrastructure systems, businesses and households to a certain urban area; (2) develop a suite of disruption scenarios for the model; and (3) to devise a metric for resilience of infrastructure systems in an urban area that could be derived from the simulation model. Our study resulted in an application of a model that mimics infrastructure systems, businesses, and households in an urban area. Subsequently, a metric for resilience of infrastructure systems was proposed and applied. The metric - supply-at-risk - was shown to be useful in comparing developments to infrastructure systems in terms of resilience. Our simulation experiment has shown that the supply-at-risk curve moves down after beneficial change is made to the system. We concluded that the supply-at-risk is a useful metric for resilience assessment allowing comparison of various infrastructure developments. Ideas for future research were also identified centered around assessing the metric under a wider range of disruptions and modifications to infrastructure systems.