A method for requirements capture and specification based on disciplined use cases and screen mockups

We present a novel method for capturing and writing requirements specifications that enriches disciplined use cases with screen mockups. Disciplined use cases are characterized by a quite stringent template, which allows to impose a large number of constraints helping to prevent common mistakes and to increase the quality of the specifications. Disciplined use cases are expressed using natural language, but the strong structuring allows to reach a good level of precision without having to introduce new (and more complex) notations. Screen mockups associated with the steps of the scenarios present the corresponding GUIs as seen by the human actors before/after the step executions, improving the comprehension of the requirements, and allowing also to precisely present non-functional requirements of the user interface. The method has been successfully applied in an industrial project and the effectiveness of the screen mockups has been validated by means of controlled experiments.