Over on his blog, Peter Seibel questions Fred Brooks oft quoted (well, paraphrased) “nine women can’t have a baby in a month”.
Seibel’s point is that one woman (or, one couple) isn’t too likely to have a baby in 9 months either, as statistically the chances of any given couple conceiving and carrying a baby to term is only 13.6%. That’s not so good if you have a hard deadline. Seibel’s recommendation is to throw bodies at the problem—three couples would have a 35.4% chance of meeting a nine-month deadline, or sixteen couples to get a 90% chance.
The problem here is that sixteen couples trying to make a baby isn’t really one project that might or might not make the nine month deadline, it’s sixteen similar projects, each trying to make the deadline. Chances are one of those projects will succeed.
Sounds like a convincing argument for the value of lots of small projects all trying to do the same thing—and when you’re talking about writing free software you also get the benefits of competition between the groups and of leveraging the work other groups are doing.
So, is it Brooks or Seibel? It looks to me like it’s a little bit of both.