Eliciting contextual requirements at design time: A case study

Abstract

The need to consider context in order to understand requirements is established in requirements engineering. Recently, this has been discussed more intensively for sociotechnical systems, which offer a rich spectrum of different operating contexts. Contextual requirements proved valuable to model requirements together with the context they are valid in, but there is a lack of research on how to derive them from stakeholder needs. Our goal in this paper is to explore the usefulness of existing requirements elicitation techniques for the identification of contextual requirements early, i.e. at design time. In a case study we investigate end-user viewpoints, together with interviews, scenarios, prototyping, goal-based analysis, and groupwork as a means to elicit and clarify contextual requirements already at design time. In our case study a certain combination of the applied requirements elicitation techniques stood out as most beneficial for the identification of contextual requirements. In addition, we discovered valuable indicators of differences in the operative context, for example when end-users cannot agree on refinements of specific requirements. Designers and operators of adaptive systems might benefit by taking such conflicts and resulting contextual requirements into account.