A common misconception is that projects rotate around the Project Manager. This is not so. They really rotate around the Project Sponsor.
The Sponsor is the person with the connections to the Executive Committee, his or her peers, the Steering Committee, key resources and others. It is the Sponsor who can make things happen.
The Project Manager can make things happen only within their sphere of influence, which is limited.
The relative roles and relationships between the Project Sponsor and Project Manager are illustrated in the following Project Governance Structure model:
This Framework should be read carefully as there is a lot of information in the connections between the parties.
The Project Governance Structure Framework makes clear the interrelationships across the project and into both the business and IT. The core team (in burgundy) need the support of the other entities to be successful.
As a member of the Governance team, you need to understand and ensure all of these relationships are known, acknowledged and being managed effectively.