1. CIPS Official Course Book - L5M8 Innovation in Procurement and Supply. The standard project management lifecycle model presented in CIPS materials outlines the 'Initiation' or 'Concept and Initiation' phase as the point where a project is defined, its feasibility is confirmed, and it is formally authorised. This authorisation includes the project charter which contains the preliminary budget and scope, leading directly to the project kick-off. (Note: Specific page numbers vary by edition, but this is covered in the chapter on Project Management).
2. Project Management Institute. (2017). A Guide to the Project Management Body of Knowledge (PMBOK® Guide) (6th ed.). The Initiating Process Group includes the 'Develop Project Charter' process (Section 4.1). The project charter is the document that "formally authorizes the existence of a project and provides the project manager with the authority to apply organizational resources to project activities" (p. 75). This includes the approved summary budget. The kick-off meeting is described as a key activity for stakeholder alignment at the start of the project, typically concluding the initiation phase or starting the planning phase.
3. Kerzner, H. (2017). Project Management: A Systems Approach to Planning, Scheduling, and Controlling (12th ed.). Wiley. In the discussion of project lifecycles, the initial phase (often termed 'Feasibility' or 'Initiation') is where "initial budget estimates are made" and upon approval, the project is formally started with a kick-off meeting to assemble the team and stakeholders. (Chapter 3: Project Management Life Cycles).