The chicken was the egg's idea for getting more eggs Alan Fletcher, The Art of Looking Sideways recursionparadox
Complete and consistent requirements An architect who needs complete and consistent requirements to begin work, though perhaps a brilliant builder, is not an architect. Mark W. Maier & Eberhardt Rechtin, The Art of Systems Architecting What the problem isThe heart of systems engineeringA late change in requirements is a competitive advantage architecturedesign