Write a five-case business case

Help me write a five-case business case.
Inputs: proposal material; stage; organisation guidance.

1. Assess strategic, economic, commercial, financial and delivery cases.
2. compare doing nothing and alternatives.
3. expose assumptions, evidence gaps and approval gates.

Deliver: Business case, Evidence and analysis gaps, Approval checklist.
Clarify critical gaps, separate facts from assumptions, and do not invent data, citations or completed actions.

My material: [fill in here]

Before you start

Provide proposal material; stage; organisation guidance.