The Tick Mark Becoming a Test
Accountants have always had a model and forgot it . Every accountant already believes fiercely in invariants; but they just don't use that specific word. But they understand the idea. The whole pedagogy is this: you already know what should be true. Now say it out loud, in a form the machine can check. That is the tick mark becoming a test. Because it is a test, techniques like Lean, Six Sigma, Total Quality Management, and Agile can be applied. And because of that, reliable, repeatable, scalable industrial processes can be created. The simplicity trap . A spreadsheet feels simpler than a model, and that is true. But that simplicity comes from the limited expressive power of the spreadsheet. A model can represent far more than a spreadsheet ever could. It carries information, structure, and metadata that a spreadsheet discards, and it makes explicit the assumptions a spreadsheet leaves unstated. The additional complexity is not accidental: it exists because the model is holding mor...