Towards Modular Certification using Integrated Model-Based Safety Cases

Software-intensive systems are characterized by an increasing number of features implementing complex functionalities. In many domains, these new functionalities perform more and more safety-critical tasks. To argue about the safety of such systems, Safety Cases are a proven technique that allows a systematic argumentation. Safety Cases may contain complex arguments that can be decomposed corresponding to modular system artifacts. This paper illustrates how a model-based system design can be tightly integrated with safety case arguments, to demonstrate both how safety cases link safety-specific analysis techniques like FMEA or FTA to architectural elements to provide evidence for safety argumentation, as well as how safety cases can be directly applied to efficiently guide the construction of the system architecture w.r.t. the claims given in the safety case. We demonstrate how existing information about the system and toolassisted techniques (e.g. formal verification, statistical testing) can be integrated into a safety case for a convincing argument in a seamless model-based development environment.