On a systematic perspective on risk for formal safety assessment (FSA)

In the maritime domain, risk is evaluated within the framework of the Formal Safety Assessment (FSA), introduced by the International Maritime Organization in 2002. Although the FSA has become an internationally recognized and recommended method, the definition, which is adopted there, to describe the risk, seems to be too narrow to reflect the actual content of the FSA. Therefore this article discusses methodological requirements for the risk perspective, which is appropriate for risk management in the maritime domain with special attention to maritime transportation systems. A perspective that is proposed here considers risk as a set encompassing the following: a set of plausible scenarios leading to an accident, the likelihoods of unwanted events within the scenarios, the consequences of the events and description of uncertainty. All these elements are conditional upon the available knowledge (K) about the analyzed system and understanding (N) of the system behavior. Therefore, the quality of K and the level of N of a risk model should be reflected in the uncertainty description. For this purpose we introduce a qualitative scoring system, and we show its applicability on an exemplary risk model for a RoPax ship.