Risk assessment of critical infrastructures: A methodology based on criticality of infrastructure elements

The assessment of risk for critical infrastructures (CIs) is a crucial aspect in ensuring the security of every country. It is imperative to have an appropriate methodology that can effectively provide adequate measures to prevent or mitigate potential impacts of hazards that may disrupt the operation of CIs. This paper presents a methodology for the risk assessment of critical infrastructure that addresses three key aspects: (a) suitability for cross-sector systems, (b) capturing dependencies and interdependencies amongst CIs, and (c) ensuring a multi -hazard approach. The proposed methodology focuses on the criticality assessment of CI elements resulting from the loss of their functionality, and the evaluation of the probability of functionality loss for these elements. By combining these assessments, the final results, which portray the risk picture, are presented through a risk matrix in a simple and explicit manner. This approach facilitates better communication with stakeholders by providing a simple and explicit depiction of the risk levels associated with CIs. To illustrate the practical implementation of the proposed methodology, a case study is presented in this paper. The results obtained from the application of the methodology highlight the most critical elements within CIs, which pose the highest level of risk.