Contract Based ISO CD 26262 Safety Analysis

The Integrated Project Speeds has developed a contract based approach to systems engineering and analysis of safety relevant applications. The paper discusses the usage of this approach for ISO CD 26262 compliant construction of safety cases, using so called safety-patterns in formalizing safety contracts. This approach enforces a characterization of allowed environment of developed items, and characterizes the possibly mode-dependent failure-propagation behavior as well as guaranteed nominal and degraded functionality within promises of such safety constructs. The method is supported by various analysis tools. These allow in particular to assess, whether a partitioning of system safety requirements to components requirements, all expressed in terms of safety contracts, are sufficient to establish system level safety requirements.