  It is widely accepted that understanding system requirements is important for
software development project success. However, this paper presents two novel
challenges to the requirements concept. First, where many plausible approaches
to achieving a goal are evident, there may be insufficient overlap between
approaches to form requirements. Second, while all plausible approaches may
have sufficient overlap to state requirements, we cannot know that unless all
approaches are identified and we are sure that none have been missed. This
suggest that many, if not most, software projects may have too few requirements
drive the design process, and that analysts may misrepresent design decisions
as requirements to compensate.
