Evaluation of a systematic approach in variant management for safety-critical systems development

The development of highly integrated, safety-relevant automotive functions is faced with the challenge of increasing complexity resulting from product customization and variants in implementation through software-hardware solutions. In order to reduce development time in this scenario, systematic reuse of engineering artifacts is important. This paper introduces a systematic model-based engineering approach that combines architecture design, requirements engineering, and safety analyses with variant management and provides evaluation results to address these challenges. In detail, this tool-supported approach achieves a new level of seamless safety engineering across variants by enabling typical safety lifecycle artifacts to be represented in a homogeneous, UML-compliant model notation. Safety-related information is no longer scattered in various isolated tools and formats, but instead consolidated and integrated. A further and decisive benefit of this notation is that variability can now be expressed and managed easily by regular variant management tools with UML adapters. Together with change-impact analysis, which is facilitated equally the ultimate goal of developing and maintaining modular safety cases can be achieved. Examples on how to use this model-based safety engineering method for variant-rich automotive functions are presented for a hazard analysis, a fault tree analysis and for a safety concept specification.