Well - I'd have to completely disagree with that idea :-)<p>Not the paper and pen bit - but the idea that planning everything up front is always the most effective route.<p>I don't think that I've <i>ever</i> had a project of significant size that hasn't had schema changes throughout it's lifetime. Not because of lack of planning - but because requirements change and we always discover more as we start putting live code in front of real users.<p>So - since schemas almost always change - I'd <i>vastly</i> prefer that we get good at changing them as <i>early</i> in the project as possible, so that we can get the kinks worked out before we start effecting a significant number of real users.