Critical Infrastructures (CIs) now include complex cyber-physical systems, with communication networks enabling interactions between the cyber and physical systems. Although the digitalization of such critical infrastructures is intended to increase performance and safety, it also subjects them to new forms of attack. Contemporary attacks that combine both cyber and physical elements are often targeting these critical infrastructures. Recent incidents have shown that it is important to have a holistic view of a CI, including the communication networks at its core, in order to understand the potential attacks on it, as well as the consequences. It is therefore imperative to analyze potential cascading effects enabled by dependencies between the various assets in such a Critical Infrastructure. In this chapter, we describe an approach to modelling the dependencies between assets in a CI and analyze the potential for, and the nature of, these cascading effects.