Communicating conflict and ambiguity in requirements engineering

Abstract

Effective requirements engineering in the presence of imperfection remains a major research problem. There is a lack of metaphors to aid communication about such imperfections during consultation with stakeholders. The aim of this thesis research is to improve the identification, communication, and handling of ambiguity and conflict in non-functional requirements, inadvertently introduced during the RE process. The thesis proposes a new approach based in the jigsaw puzzle metaphor, which is a novel contribution in the area of visual metaphors, and as a communication mechanism to make conflict and ambiguity explicit during stakeholder consultation meetings. This metaphor is based on jigsaw puzzles, where each puzzle piece represents a requirement. When the requirement text contains ambiguities and/or conflicts with other requirements, the respective puzzle pieces almost fit together but not perfectly. The approach presents heuristics to identify the most pertinent conflicts and ambiguities to handle and thus to make explicit through the badly-fitting matches. The gamming nature of the jigsaw puzzle metaphor, the fact it presents an easy to understand and learn language, as well as the analogy with misshapen graphical visualization (the badly-fitting matches) to represent that there is a problem, and its adequacy to a creative task as RE is; altogether are key characteristics that contribute to the adequacy and success of the jigsaw puzzle metaphor when used in stakeholder consultation meetings. In fact the jigsaw puzzle metaphor used together with the proposed method for conducting the consultation meetings with the stakeholders proved successful in:  Increasing effectiveness when compared with text presentation.  Fostering team work and communication, and improving commitment of stakeholders in co-authoring of requirements and co-responsibility in ambiguity and conflict handling.  Promoting a relaxed environment to improve team cooperation and creativity. A key contribution of this thesis is its focus on separating the processing of the information about the imperfection from the issue of communicating that imperfection. Such a separation, though critical, has not been proposed to date.