Fluent-based animation: exploiting the relation between goals and scenarios for requirements validation

Scenarios and goals are effective and popular techniques for requirements definition. Validation is essential in order to ensure that they represent what stakeholders actually want. Rather than validating scenarios and goals separately, possibly driving the elaboration of one through the validation of the other, This work focuses on exploiting the relation between goals and scenarios. The aim is to provide effective graphical animations as a means of validating both. Goals are objectives that a system is to meet. They are elaborated into a structure that decomposes declarative goals into goals that can be formulated in terms of events that can be controlled or monitored by the system. Scenarios are operational examples of system usage. The relation between scenarios and goals is established by means of fluents that describe how events of the operational description change the state of the basic propositions from which goals are expressed. Graphical animations are specified in terms of fluents and driven by a behaviour model synthesised from the operational scenarios.