NIVERSITY Requirements Engineering With Viewpoints

The process of understanding the system under analysis, the services required of it, its environment and associated constraints involves the capture, analysis and resolution of many ideas, perspectives and relationships at varying levels of detail. We believe requirements methods based on global reasoning lack the expressive framework to adequately articulate this distributed requirements knowledge structure. This paper describes the problems faced in trying to establish an adequate and stable set of requirements and proposes a novel ViewpointOriented Requirements Definition method (VORD) as a means of tackling some of these problems. This method structures the requirements engineering process using viewpoints which are associated with sources of requirements. The paper describes VORD in the light of current viewpoint-oriented requirements approaches and shows how its improves on them. A simple example of a bank auto-teller system is used to demonstrate the method.