Vulnerability analysis of interdependent infrastructure systems

As resilience of infrastructure systems gains importance to deal with the uncertainty related to extreme natural events, there is increasing emphasis on the design of systems that do not fail catastrophically. The consequences of a perturbation on a system depend both on the magnitude of the perturbation and the vulnerability of the system. The assessment of the vulnerability of infrastructure systems presents the challenge of dealing with their complexity. This paper presents a method to identify the elements of a system which have the potential to trigger cascading failures thus making the system vulnerable. A new predictive metric (X1) is introduced and variations in the system parameters that could affect its predictive capabilities are explored. Networks which have properties comparable to real-world infrastructures such as transportation and utility supply systems are simulated. It is found that the correlation between the new metric and the behaviour of the system holds across all the spectrum of the
simulations performed.