The Art of Systems Architecting A Book by Mark W. Maier & Eberhardt Rechtin www.amazon.com Complete and consistent requirements systems
The requirements of economy Economy is the mother of most inventions, not necessity, unless in the sense of poverty and hardship. A requirement for convenience is simply a diluted requirement for ease and economy. It seems to be invariably true that those characteristics which lead people to call a design functional are derived from the requirements of economy and not of use. David Pye, The Nature and Aesthetics of Design Form follows functionEconomy of material and labor function