Why yes, that has occurred to me. It's possible. But I doubt it for reasons I explained above. The few successful Lean Manufacturing adoptees in the US are on the smaller side as well. That's not because it doesn't scale, as Toyota is now the world's largest car manufacturer. It's because small companies can make cultural changes more easily. See the This American Life episode on NUMMI for a poignant illustration of that.
I think the answer to this question in software will come from companies that have started small with something like XP and grown into large companies. I suspect you'll end up with something like the cellular model that bodies use to scale. That's how it seems to be going at the companies I've visited. One startup I know is at 50 or so engineers and they are doing fine with a lot of small teams working semi-independently, releasing daily, and coordinating as they see fit. Or take YouTube. They have a few hundred people but they maintain a weekly (or more often) release schedule, power works in a bottom-up fashion, product management is decentralized, and the teams are loosely joined. It works fine for them.
I think the answer to this question in software will come from companies that have started small with something like XP and grown into large companies. I suspect you'll end up with something like the cellular model that bodies use to scale. That's how it seems to be going at the companies I've visited. One startup I know is at 50 or so engineers and they are doing fine with a lot of small teams working semi-independently, releasing daily, and coordinating as they see fit. Or take YouTube. They have a few hundred people but they maintain a weekly (or more often) release schedule, power works in a bottom-up fashion, product management is decentralized, and the teams are loosely joined. It works fine for them.