Teams Of Up To Twelve

I'm already fed up of the XP won't scale refrain, so here goes.

The relevant metric here is ProportionOfUse? -- what proportion of real software use per day globally is of systems written by a team bigger than this. My completely unscientific answer: statistically insignificant to the vital job of making the world a safer and happier place. Many more such projects get started than used of course. Once you add a weighting for the user joy in employing the system the big team disappears further down the plug hole where it belongs. But then maybe I'm biased.

Doesn't Microsoft, the maker of software used on over 90% of the world's computers, use teams of many more than twelve persons? Please correct me if I'm wrong.

Before anyone else answers, please note that there's a difference between a team of more than twelve, and a team made of up TeamsOfUpToTwelve. While Microsoft may have used many engineers to develop Windows, Office, etc., did they work in atomic teams of more than twelve?