Model-based safety assessment with SysML and component fault trees: application and lessons learned

Mastering the complexity of safety assurance for modern, software-intensive systems is challenging in several domains, such as automotive, robotics, and avionics. Model-based safety analysis techniques show promising results to handle this challenge by automating the generation of required artifacts for an assurance case. In this work, we adapt prominent approaches and propose to augment of SysML models with component fault trees (CFTs) to support the fault tree analysis and the failure mode and effects analysis. While most existing approaches based on CFTs are only targeting the system topology, e. g., UML class diagrams, we propose an integration of CFTs with SysML internal block diagrams as well as SysML activity diagrams. We realized our approach in a prototypical tool. We conclude with best practices and lessons learned that emerged from our case studies with an electronic power steering system and a boost recuperation system.