Analyzing Cascading Effects in Interdependent Critical Infrastructures

Abstract

Critical Infrastructures (CIs) are resources that are essential for the performance of society, including its economy and its security. Large-scale disasters, whether natural or man-made, can have devastating primary (direct) effects on some CI and significant indirect effects (cascading effects) on other CIs, because CIs are interconnected and depend on each other’s services. Recent work by Laugé et al. expressed the dependency values among CIs as dependency matrices for various durations of the primary CI failure. For better preparedness and mitigation of CI failures knowledge of the weak points in CI interdependencies is crucial. To this effect, we have developed a MATLAB code that identifies the forward paths and loops between pairs of CIs based on a simplified version of Laugé’s matrices. The code calculates the parallel forward paths and loops dependencies to identify and quantify the amplification of cascading effects of any disruption that might hit one of the CIs included in the research. A main consequence, which has implications for expert assessment of dependencies between CIs, is that the cascading effects are not limited to the direct values expressed in the dependency matrices.