The DeSCAS Methodology and Lessons Learned on Applying Formal Reasoning to Safety Domain Knowledge

Functional safety has become an important aspect for engineering activities in the automotive domain due to the upcoming introduction of the safety standard ISO 26262. This paper proposes a methodology to guide the safety related requirements engineering process by means of OWL (Web Ontology Language) ontologies. These ontologies formalize necessary domain knowledge and serve as reference models to support semi-automated requirements discovery and to ease the certification process. Using OWL’s logical base, knowledge inference is applied to reason about safety measures for ensuring compliance with the reference process (guidance). The proposed methodology has been implemented in a prototype toolchain and applied to a simple lane departure warning system as an example assistance and automation system. Lessons learned refer to conceptual (expressiveness) and technical (tooling efficiency) issues.