Towards a Graphical Specification of Operational Rules in RiskSpectrum ModelBuilder

Model Based Safety Assessment (MBSA) tools encapsulate dependability expertise in the definition of high-level components. Detailed (formal) description of component behavior and interactions can be created by an expert and exposed to users only on the level required for building system models. Knowledge Bases in RiskSpectrum ModelBuilder (KB3) implement this separation by offering an analyst a library of graphical components with their properties and possible connections. Component behavior and interactions are pre-defined using the modeling language Figaro. This includes also operational rules that steer the system under study. We generalize our experience from real-life projects that developed such Knowledge Bases. We investigate how a common graphical formalism such as flow charts can be used, in connection with the Figaro language, to structure the Knowledge Base creation and facilitate quality of the final code. The proposed method takes a graphical specification of operational rules satisfying certain additional conditions on input and guides the Knowledge Base creation process. This is the first step towards automatic generation of the Figaro code from a graphical specification.

Keywords: Model based safety assessment, Knowledge bases, Figaro, Graphical specification.

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