Quantitative Assessment of Nonfunctional Requirements in Product Families

Abstract

Modelling nonfunctional requirements, along with many other NFR-related concerns, have not been addressed properly in the literature. Although nonfunctional requirements (or quality attributes) are important, they are the most expensive and difficult to deal with since they are (mostly) specified qualitatively not quantitatively, and also due to the fact that nonfunctional requirements may have interdependencies among each other leading to inconsistency in requirements specification. Moreover, the adoption of the concept of product families into the software industry led to the ability today to build families that share features. This indicates the significance of software families. Accordingly, in this research, not only do we study nonfunctional requirements in a systematic way, we also attempt to examine them from the perspective of software families. We highlight the need for developing a better quantitative assessment technique for nonfunctional requirements. Then, we propose a formal approach to the assessment of nonfunctional requirements in software product families.