uxzentrisch zitiert:

»Here is one of the few effective keys to the design problem – the ability of the designer to recognize as many of the constraints as possible – his (or her) willingness and enthusiasm for working within these constraints – the constraints of price, of size, of balance, of surface, of time, etc.; each problem has its own particular list.«

Charles Eames, 1967; entnommen aus den Unterlagen des Workshops »Interaction Design«, UX Intensive in Berlin.
Die Gültigkeit davon lässt sich ohne Weiteres auf UX-Design übertragen, wie ich finde.