An Initial Approach to Reuse Non-Functional Requirements Knowledge

Non-Functional Requirements (NFR) can be seen as qualities that software should deliver to cope with the stakeholders’ demands. NFRs are fuzzy in nature and hence hard to identify. Despite the fact that both developers and users may value NFRs, they frequently do not identify the need for an NFR. Even when an NFR is identified as required, possible solutions to implement this NFR may be hard to figure out. Furthermore, interdependencies among NFRs may implicate that a solution for one NFR may, at the same time, bring synergy to one NFR while conflicting with another. One approach to deal with that is to use Softgoal Interdependency Graphs (SIG) to capture knowledge describing alternatives to implement NFRs. We have obtained empirical evidence that using catalogues can help eliciting NFRs despite the fact that catalogues do not scale too well. To address this question, we have investigated the use of ontologies and semantic web techniques to represent SIGs in a machine readable format. We have produced a tool (NDR) that starts to use these concepts. In its current form, the NDR tool only allows very basic queries done manually. The NDR tool is part of the NDR framework which will facilitate the reuse of NFR knowledge on Alternatives to incorporate NFRs into the design of target systems.