Quantitative evaluation of the synergistic effects of failures in a critical infrastructure system

AbstractA critical infrastructure is a complicated system whose failure (in whole or in part) has a significant impact on national interests, including security, the economy and basic human needs. The system consists of relevant sectors, elements and their mutual linkages. In order to study critical infrastructures, it is necessary to apply a systems approach based on cross-sectoral evaluation and research into the linkages between the individual critical infrastructure sectors. Specifically, it is necessary to describe the individual vertical and horizontal levels of each critical infrastructure and the associated linkages. From this point-of-view, a critical infrastructure is embedded within the broader context of emergencies and enterprises, representing a compact and mutually-interconnected system.This paper focuses on quantitatively assessing the impacts of critical infrastructure failures. It presents a theory of synergistic linkages, their levels and the synergistic effects due to the joint action of impacts, which increase the overall impact on the critical infrastructure and on society. The concepts are formalized in the SYNEFIA methodology, which is applied in a case study involving the critical infrastructure of the Czech Republic. In particular, the methodology is applied to determine the synergistic effects of disruptions to multiple sub-sectors of the Czech infrastructure