Checkable Safety Cases: Enabling Automated Consistency Checks between Safety Work Products

Abstract

In the automotive domain, the employment of agile development is currently hindered by the fact that the safety lifecycle, which implies the creation and maintenance of safety work products, is manually executed, being a complex and expensive process. Given a change in the system under consideration, ISO 26262 recommends that the impact of that change on the safety case of the system shall be assessed and that the safety case shall be correspondingly updated. To this end, in this paper, while assuming a model-based system and safety engineering context, we propose checkable safety case models, which are semantically rich safety case models integrated with system and safety engineering models (i.e., work products of a model-based safety lifecycle). The semantically rich specification and the model integration allow for automated consistency checks between the safety case and the system, specifically its engineering models. We exemplify our contributions via an in-vehicle driver assistance system for driving through intersections.