Scenario-Based Validation: Beyond the User Requirements Notation

A quality-driven approach to software development and testing demands that, ultimately, the requirements of stakeholders be validated against the actual behavior of an implementation under test (IUT). In model-based testing, much work has been done on the generation of functional test cases. But few approaches tackle the executability of such test cases. And those that do, offer a solution in which test cases are not directly traceable back to the actual behavior and components of an IUT. Furthermore, extremely few approaches tackle non-functional requirements. Indeed, the User Requirements Notation (URN) is one of few proposals that address the modeling and validation of both functional and non-functional requirements. But if the URN is to support traceability and executability of tests cases with respect to an actual IUT, then the “URN puzzle” must be modified: it must be augmented with a testable model for functional and non-functional requirements, an IUT, and explicit bindings between the two. We explain how these three additions are used in our implemented framework in order to support scenario-based validation.