Well, there are many things to disagree on. Many where already listed. These I haven't found yet: 1. I real baby doesn't always take 9 months. The same goes fo

Well, there are many things to disagree on. Many where already listed. These I haven't found yet: 1. I real baby doesn't always take 9 months. The same goes for software. Even if you get over the first few hurdles it is still a guessing game how long it takes. In fact Chinese people even say it takes 10 months for the baby to come out. 2. While the idea proposed by the author, that you can let teams work in parallel to increase predictability of the results, might have many flaws, I actually believe it pays out to think like that, because there are individuals and teams who work way, way better than the average coder/team. If you let 3 teams tackle the same problem at the same time one of them might yield a much better result than the others, and in that case will probably do it even faster. And the next time you can just let the single best team work on a problem and make a better profit margin.