as far in advance of project planning as possible,

The project manager is appointedand even better during the process of developing the project charter.
Input Tools and Techniques Outputs Contract Statement of Work (SOW) Environmental and Organisational Factors Organisational Process Assets Project Selection Methods Project Management Methods Project Information Systems Expert Judgement Project Charter 5.2 Developing the Project Scope Statement (Preliminary) The project scope statement is the definition of the project - what needs to be done.