Integrating Goal Model Analysis with Iterative Design

Context and Motivation: Goal-oriented methods can be used by analysts to produce a set of system requirements that reflect the customer needs and are used as guidelines in the subsequent system design, in which a model of the system is produced. The design model is used to analyze the coherence of the system behavior with the requirements. Question/problem: Design is an exploratory activity. Before the final model is developed, different alternatives are explored and models evolve back and forth from partial to complete. Partial models embed portions that are currently left unspecified and will later be refined. Recent formal verification techniques allow the designers to verify the satisfaction of requirements even for partial models. However, there is still no way to interpret the results of the verification over the original goal model. Principal idea/results: The ability to reflect the results of verification back to the goal model would improve the design process by making the developer aware of the consequences of design choices on goal satisfaction. It would also support early detection of design errors and improve requirements negotiation between designers and requirements analysts. Contribution: This paper proposes COVER, a unified framework to support goal model analysis during software design. COVER allows the goal model produced by the requirements analysts to be kept alive and updated while the system is designed. At each development round, the model is verified against the requirements of interest and the verification results can be used to update either the design model or the goal model.