From an interview with Valve’s Gabe Newell:

Specialization and hierarchy are the norms in film production, and are antithetical to what needs to happen in the games industry. The reason for that distinction is that the game industry is more focused on invention than on repeatability/measurability.

That may be true at Valve where they can release whenever the hell they want, but here it’s all about measurability and specialization. I don’t know whether that is a sad fact about the rest of the industry or just a valueless distinction. Specialization helps measurability. If you know upgrades to System X take 100 hours because you’ve been doing upgrades of that type for the last six cycles, then that is valuable to reducing risk.

Not a particularly efficient or innovative way to run a company, but more realistic.