Component-Aware Triggered Scenarios

Use-case scenarios, with notations such as UML sequence diagrams, are widely used to specify software system behavior. Although intuitive, these notations allow engineers to specify behaviors with unintended semantic side-effects. To address these inconsistencies, one class of languages targets triggered scenario specifications for expressing a system's reactive behaviors. However, these languages lack adequate facilities for modeling the intended behavior of the individual system components. This runs the risks of sacrificing the expressive power required to model component behaviors, misinterpreting the stakeholder intent, and misspecifying the component behaviors. The risks are particularly prominent when the requirements specification and software architecture specification are refined iteratively and in parallel. To remedy these problems, we propose component-aware Triggered Scenarios (cats), an enhancement to triggered scenario languages that allows an engineer to define components' obligations within a scenario. We have formalized the syntax and semantics of cats, and have applied cats on a real-world case study, which suggests improved accuracy and conciseness of cats in comparison to existing alternatives.