Vulnerability Analyses of Interdependent Critical Infrastructures: Case study of the Swedish National Power transmission and Railway system

Critical infrastructures provide services that are essential for the functioning of our society and extensive disruptions in these can have widespread effects. These effects are not only limited to the directly affected infrastructure but also indirectly through interdependencies to other infrastructures. By only account-ing for the direct consequences when analysing critical infrastructures, the total consequences can potentially be severely underestimated. Identifying vulnerabilities in these system-of-systems is hence highly critical for holistic risk management. This paper uses a modelling approach for interdependent technical infrastructures and presents a case study using real-life data and models of the Swedish national power transmission system and Swedish national railway system, taking into account both functional and geographical interdependencies. It is concluded that it is of importance to include effects of interdependencies when analysing critical infra-structure vulnerability and that these types of analyses give valuable insights for proactive management and aid our understanding of interdependent critical infrastructures.