Non-functional Requirements in Architectural Decision Making

Software architects often must work with incomplete or ill-specified non-functional requirements (NFRs) and use them to make decisions. Through this process, existing NFRs are refined or modified and new ones emerge. Although much research has centered on how software architects treat NFRs, no empirical studies have investigated the state of the practice. A survey based on interviews with 13 software architects addressed two fundamental issues: how do architects face NFRs from an engineering perspective, and how do NFRs influence their decision-making? The survey revealed that architects usually elicit NFRs themselves in an iterative process; they usually don't document the NFRs and only partially validate them.