Using Scenarios to Discover Requirements for Engine Control Systems

Rolls-Royce control systems are complex, safety critical and developed in ever-compressed timescales. Scenario techniques are utilised during systems design, safety analysis and systems verification. Scenarios can be used to improve requirements quality and to ensure greater confidence in requirements coverage for both normal and exception behaviour. A study was undertaken to investigate whether the ART-SCENE process and tool could enable engineers to identify exception behaviours earlier in the system design process, thus reducing cost and improving quality. ART-SCENE provides automatic generation of scenarios and alternative course events through the Scenario Presenter. These recognition cues are used to prompt engineers to identify deviations that may otherwise be missed. This paper describes a comparative evaluation between ART-SCENE and a standard hazard identification technique to assess the effectiveness of this approach.