Model-based approaches have long been premised on the fact that it is an order of magnitude cheaper to change an exploratory diagram at feasibility than it is to make the same change to the production code, as evidenced by studies carried out in the early 1980s. E-business reinforces the impact of this message by raising the bar for high-quality software. No longer is software designed for single, known individual users; it is designed for vast numbers of anonymous users.