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 time to market 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 changeimpact analysis which is facilitated equally by this model-based foundation, 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.