Having worked for huge organisations, I must say systems are rarely designed well. Their influences across all disciplines are hardly ever fully considered. From one side I agree that one should avoid paralysis through analysis and that eventually some programming must commence. On the other hand, the badly designed systems come in large packs. As a consequence, putting stress and strain on the organisation and eventually affecting the bottom line.
A good op's input will inevitably be of great value to system designers, as the latter usually have no hands-on experience in the concepts they studied. Indeed, input from all affected disciplines is valuable. Until utopia (CMM level 5) is reached.