Projects are often complex and full of uncertainties. A #Big_Picture helps make the essential aspects tangible:
Deliverables and scope: What belongs to the project? What is deliberately excluded?
Stakeholders: Who is involved, who is affected?
Milestones and phases: Which steps are planned, which dates are critical?
Risks and constraints: Which external factors influence the project?
https://marc-widmann.de/en/big-picture-in-project-management