Graphical formalisms for modeling critical infrastructures

Modelling and simulation are well-suited approaches to analyse critical infrastructures (CIs), providing useful insights into how components’ failures might propagate along interconnected infrastructures, possibly leading to cascading or escalating failures, and to quantitatively assess the impact of these failures on the service delivered to users. This chapter focuses on the usage of graphical formalisms for modelling and simulation of CIs. It fi rst identifi es and motivates the main requirements that a modelling and simulation framework for CI analysis should have. Then, it provides an overview of the available graphical formalisms, discussing how they have been used in the literature for CI analysis and assessing the extent to which they actually meet the identifi ed modelling and simulation requirements. The second part of the chapter investigates how a subset of the identifi ed requirements are actually met adopting a specifi c graphical modelling formalism, the Stochastic Activity Networks formalism, which has been extensively used by the authors of this chapter in past European FP6 projects dealing with CI analysis. Keywords: Critical Infrastructures, Modelling and Simulation, Graphical Formalisms, Modelling Requirements, Stochastic Activity Networks