Requirements Envisaging by Utilizing Scenarios (REBUS).

Abstract : Requirements envisaging is the process of transforming vague and informal requirements into precision descriptions. At the envisioning stage of system development, complex are described in a fragmentary and highly contextual manner. As a consequence, requirements envisaging, which seeks to bridge this gap, is a challenging phase of system development, which to provide automated support. In requirements envisaging, domain experts will often convey partial descriptions of system and environment behavior arising in restricted situations, namely, scenarios. Scenarios play an important role in envisaging by mediating communication and by describing alternative situations and rationale explored during design. Scenarios are not, in general, formally captured as part of requirements documentation. This dissertation is a step toward automated support for envisaging with scenarios. For this task, the representation used to capture scenarios must support human-tool collaboration. The tool descrbed herein supports capturing scenarios in a formal manner despite their fragmentary and contextual nature. The goal is to let people who are not necessarily computer experts create scenarios easily and allows people to readily understand the concepts conveyed in these scenarios. The main accomplishments reported in this thesis are: an observational study of domain and software experts utilizing scenarios, the development of a formal representation for scenarios, an automated tool that allows people to create scenarios in that representation, and evaluation of the representation and tool in a real world domain outside those studied during development.