Abstract. This paper presents the analysis and key findings of a survey about
dealing with non-functional requirements (NFRs) among architects. We find that,
as long as the architect is aware of the importance of NFRs, they do not adversely
affect project success, with one exception: highly business critical modifiability
tends to be detrimental to project success, even when the architect is aware of it.
IT projects where modifiability is perceived to have low business criticality lead
to consistently high customer satisfaction. Our conclusion is that modifiability
deserves more attention than it is getting now, especially because in general it
is quantified and verified considerably less than other NFRs. Furthermore, IT
projects that applied NFR verification techniques relatively early in development
were more successful on average than IT projects that did not apply verification
techniques (or applied it relatively late in development).
Keywords: Software Architecture, Requirements Management, Software Project
Management, NFR, Modifiability, Empirical Software Engineering.