Specification of Non-Functional Requirements: A Hybrid Approach

When specifying user requirements, not only it is critical to ensure correct and unambiguous specification of functional requirements, but also that of non-functional requirements (NFRs). In fact, resolving ambiguities from user specified natural language NFRs and specifying the correct ones in a formal language have attracted significant attention. Our current research focuses on the issues pertaining the same. We observe that it is a usual practice for a user to narrate the NFRs in natural language and the requirement engineers manually try to express the same, using some semi-formal or formal language notations. However, inaccurate and the laborious manual approach may fail to detect all the NFRs and correctly remove the ambiguities in those detected. Hence, current research attempts have focused on automating the conversion of natural language NFRs to formal notations. In literature, there exist numerous approaches that take requirements as input and output the extended UML counterpart including NFRs. However, majority of the approaches do not support ambiguity resolution and verification of the extracted NFRs that are fairly essential. In this paper, we propose and discuss a hybrid approach viz. NFRs-Specifier, that attempts to resolve ambiguities, extract NFR’s, perform verification and generate NFRs specification by means of the extended UML model.