Process/sup NFL/: a language for describing non-functional properties

Nonfunctional requirements (NFRs) are rarely taken in account in software development. There are reasons that help us to understand why these requirements are not explicitly dealt with: their complexity NFRs are usually stated only informally, their high abstraction level, and the rare support of languages, methodologies and tools. In this scenario, we concentrate on defining a language, namely Process/sup NFL/, that expresses NFRs during software development. This language has been designed to consider specific characteristics of NFRs like their correlations and conflicts. In order to illustrate our language, we describe NFRs of software radios and the NFRs performance and security, which are usually present in software requirements specifications.