ABSTRACT
Critical infrastructures provide indispensable services to society and extensive disruption of these give rise to large societal consequences. Most risk-related studies of critical infrastructures, however, focus rather narrowly on the direct consequences, e.g. expressed by services not supplied or cost of non-supplied services. Although these measures might serve as a proxy for the direct societal effects, they are not suitable for gaining deeper insights into higher-order societal consequences of disruptions. To this end, the inoperability input-output model can be used, where national economic data is used as an approximation of interdependencies among societal sectors. The paper demonstrates an integrated model, consisting of a physical model of a critical infrastructure and a regional inoperability input-output model. In a case study a representative model of the Swedish power transmission system, as the electric power system is generally recognized as one of the most vital critical infrastructures, and Swedish regional economic input-output data is used. The results from an analysis using this type of model can provide important information to societal risk-related decision making, e.g. by identifying regional areas characterized by both having vulnerable power supply and strong electric power dependence. The proposed integrated model constitutes a valuable advance when assessing critical infrastructure vulnerabilities and societal consequences of failures.
