An approach for creating sentence patterns for quality requirements

Requirements are usually categorized in functional requirements (FRs) and quality requirements (QR). FRs describe "things the product must do" while QRs describe "qualities the product must have". Besides the definition, classification, and representation problems identified by Glinz, there are two further problems with current definitions of quality requirements: (i) the definitions are imprecise and thus difficult to understand and apply, and (ii) the definitions provide no guidance or support for their application in a given organizational context. To tackle these two problems, we propose an approach that - given a quality attribute (e.g., performance) as input - provides a means to specify quality requirements by sentence patterns regarding this quality attribute. In this paper, we contribute a detailed presentation and description of our approach and a discussion of our lessons learnt while instantiating it for performance requirements. Additionally, we give guidance on how to apply our approach for further quality attributes. Through this approach, we aim at encouraging researchers to help us improve the precision of definitions for quality requirements and support practitioners in eliciting and documenting better quality requirements.