Bringing requirements engineering to formal methods: timing diagrams for Event-B and KAOS

摘要

Event-B is a language for the formal development of reactive systems. At present the RODIN toolkit (RODIN, 2009) for Event-B is used for modelling requirements, specifying refinements and verification. In order to extend the ability to model graphically requirements for the real-time domain, where timing constraints are essential, we use Timing diagrams for Event-B, UML-B and Knowledge Acquisition in autOmated Specification (KAOS). The Timing diagrams, based on UML 2.0 Timing diagram notation (OMG, 2007), provide an intuitive graphical specification capability for timing constraints and causal dependencies between system events. Translation schemes to Event-B, UML-B and KAOS are proposed and presented.The benefit of our contribution is providing a graphical option to generate timing constraints and causal dependencies of a reactive system to Event-B, UML-B and KAOS Goals. Thus, instead of manually generating these Event-B, UML-B and KAOS Goal models in a textual form, users can use the TD as a graphical front-end, and these target models are created automatically.We compare the three applications of the Timing diagrams in terms of their contribution to formal requirements engineering. A partial case study of a Lift System is used to demonstrate the translation in practice.