We survey the state-of-the-art on model-based formalisms for safety and
security analysis, where safety refers to the absence of unintended failures,
and security absence of malicious attacks. We consider ten model-based
formalisms, comparing their modeling principles, the interaction between safety
and security, and analysis methods. In each formalism, we model the classical
Locked Door Example where possible. Our key finding is that the exact nature of
safety-security interaction is still ill-understood. Existing formalisms merge
previous safety and security formalisms, without introducing specific
constructs to model safety-security interactions, or metrics to analyze trade
offs