PMBOK® Guide, 4th Edition
1.6 Project Management Skills
1.4.4 Role of the PMO
As we have stated, the project manager measures his success by how well he can negotiate with both upper-level and functional management for the resources necessary to achieve the project objective. Moreover, the project manager may have a great deal of delegated authority but very little power. Hence, the managerial skills he requires for successful performance may be drastically different from those of his functional management counterparts.
The difficult aspect of the project management environment is that individuals at the project–functional interface must report to two bosses. Functional managers and project managers, by virtue of their different authority levels and responsibilities, treat their people in different fashions depending on their “management school” philosophies. There are generally five management schools, as described below: