Deriving Goals from a Use-Case Based Requirements Specification for an Electronic Commerce System

Scenarios aid analysts and stakeholders in developing an understanding of current or envisaged systems and business processes [AMP94, Jac92, PTA94, WPJ98]. They describe concrete system behaviors by summarizing behavior traces of existing or planned systems. Use cases [BRJ99, Jac92], describe the possible system interactions that external agents may have with a system. In UML, scenarios are comprised of sets of actions and interactions that involve specific objects [BRJ99]. A representational framework for scenarios and use cases appears in [AP98b]. Scenario analysis is a very effective and proven technique for surfacing goals during requirement engineering. Goals are the objectives and targets of achievement for a system. Goal-driven approaches focus on why systems are constructed, expressing the rationale and justification for the proposed system.

Focusing on goals, instead of specific requirements, allows analysts to communicate with stakeholders using a language based on concepts with which they are both comfortable and familiar. For this requirements specification effort, we employed the GBRAM in which goals are operationalized and refined into requirements and point to new, previously unconsidered scenarios (for a detailed explanation of the GBRAM and its heuristics see: [Ant97]). Similarly, scenarios also help in the discovery of goals [AMP94, AP98a, JBC98, Pot99, RSB98].