Modern society heavily relies on large, heterogeneous and complex software-intensive systems to support all kinds of daily activities. Services such as urban transportation, logistics, health-care, data communication, railway, aerospace, and power distribution, to name a few, are becoming more and more dependent on the availability of such infrastructures. Any discontinuity of service may lead to serious problems, from severe financial losses to fatalities or injuries; the causes have different natures, either human errors, unexpected acts of nature, or intentional attacks like sabotage. Safety and security (S&S) assessments in critical infrastructures measure how these disruptions are handled and what is the impact suffered by the critical infrastructure under stress. These assessments are normally performed using analytical or simulation-based techniques often addressing one single specific aspect at a time rather than studying these infrastructures in a holistic manner.