Integrating Safety into System Design with SysML

Abstract

Rolls-Royce control systems are complex, safety critical systems, developed in ever-compressed timescales. Scenario techniques have been investigated, to determine if they can enhance the development process by fostering closer integration between different disciplines and by improving requirements derivation and design evaluation.A study was undertaken to investigate if aspects of the Systems Modelling Language (SysML) could integrate elements of the development process and help identify failures earlier. SysML sequence diagrams were used to provide a rigorous graphical representation of structure and behaviour of the system.A team of engineers then used the diagrams to capture wanted and unwanted system behaviour for typical functions, from which safety requirements and design questions were generated. This paper describes the background to the problem, and evaluates the effectiveness of SysML sequence diagrams as an integrating notation and aid to requirements derivation and design queries.