The one element that can change every element is the human element
Dow Chemical tag line
People are our most valuable resource--correct? Well, that's always the line, but is it the reality? Lest we all forget, the 'facts' are that on the financial balance sheet, the one executives look at, people are a liability (accrued benefits and compensation), and on the expense statement, they are a cost.
But, fortunately on the project balance sheet, they're assets. Recall: the project balance sheet and the financial balance sheet are not the same animal. The former is a view of the top down/bottom up balance in the project, and the latter is a view of the distribution of monetary ownership between the business and it's benefactors.
Bottom line: there's a natural tension between business and projects, and the human resource is a part of that tension.