Codes, regulations and rules promote survivability efforts for naval ships, but it is not defined how the results should be interacting with other safety-related goals defined by the state or recommended by NATO or classification societies.
Effectiveness, survivability, freedom of action and allowable risk levels are, for naval ships, linked. However, without a measure to assess the risks, the links and their relations cannot be fully understood and analysed. The purpose of introducing probabilistic risk assessment in the analysis would then be to meet safety and security (including survivability) goals more effectively. Studies show that quantified probabilistic risk-knowledge models will allow for comparing different alternatives and include operational risk to create a balance between risk and capability. Probabilistic-based operational scenarios allows for risk analysis of both traditional maritime safety areas and military survivability areas. The risk for different areas is therefore comparable and can be assessed specifically for a particular ship.
In this study maritime piracy is used as a case study. The purpose of the case study is to test the possibility to use expert-based threat analysis to support the definition process of safety and security scenarios. The scenarios should be defined with quantified probabilities and consistent with probabilistic risk assessment for naval ship survivability and safety development.
The study shows that it is possible to perform a threat analysis based on quantified data on the pirates’ capabilities, organisation and methods collected from experts. In relation the ships vulnerability assessment the analysis determines the capabilities and intentions of the pirates and how likely they are to carry out the defined threat. The quantified data very clearly indicates where there is a good expert agreement and where there are uncertainties among the experts. The study also shows that it is possible to use the data to create risk scenarios with quantified probabilities specifically developed for a ship and mission.