UML safety requirement specification and verification

Safely rcquircmcnis of safely critical technical systems are a demanding subset of requirements thai often ask for rigorous formal verification. Formal methods arc difficult and often not easily to understand. In this paper we present a more approachable semi-formal method using UML (Unified Modeling Language) and SysML (System Modeling Language) elements. An overview of verbally described safety requirements leads to the identification of typical properties of safety requirements. Excmplarily it is shown how safety requirements arc graphically represented with the help of UML specifications. Depending on the properties of a safety requirement its illustration in UML is more or less feasible. We present how some safety specifications can be verified in UML models of safety-critical embedded systems. Finally we summarize the presented method in a table of verbal safety requirements with their translation and possible verification in UML.