A few years ago, when I first made a slide for a talk that said "The Scope is Supposed to Creep" it felt a bit like heresy, but maybe sort of satisfying heresy. A little provocative, maybe a tad thin, but illustrating an important point: that "scope will evolve as you build and test and use".
Then we wrote it up for our blog last year, and just this month we revised it again. Each time the concept clarifies and sharpens a little, and by this point it feels like a pretty solid boulder to stand on, and perhaps a helpful resource for those budgeting for technology.
So check it out, newly revised: