What about catering and sanitation and security?

Seriously though, I don't think the point behind counting value created by every dependant into dependencies is necessarily a bad one. Surely there must be some mathematical concept that would allow to "balance" the value in a dependency network of industries.

I thought about HR after hitting the reply button but figured there was no way I was going to think of every function! I cleared my conscience by mentally bucketing all of those under "managing the business" ;-)