The project brief is submitted for approval at Gateway 1: Definition. It is the output from the project manager (PM) to articulate the concept of a business idea.
The main objective of the project brief is to produce sufficient information to define and scope the business idea and to create a vision of its importance as a project to meet a specified business need.
The PM is usually responsible for the preparation and production of the project brief, actively engaging with key stakeholders to gather the relevant input.