As all software developers know, nine women can’t have a baby in a month. Or in Fred Brooks’s more elegant phrasing: “The bearing of a child takes nine months, no matter how many women are assigned.” (The Mythical Man Month, p. 17) The point, of course, is that some tasks are, as Brooks would say, “sequentially constrained”. They’re going to take a certain amount of time no matter what — the time can’t be reduced by having more people work on them.

On the other hand, is it actually the case that one woman can have a baby in nine months? Suppose we have just been put in charge of Project New Baby that must produce a brand new baby in nine months. How should we staff the project. Easy enough — nine women can’t have a baby in a month, right? No point in overstaffing so we’ve…