A business case is a persuasion document with a financial backbone. Claude builds the structure and the narrative. You supply the numbers, the strategic context, and the judgment about what the decision-makers care about.
Claude does not build financial models, but it excels at writing the narrative around your numbers. Run your own numbers first. Then paste them into Claude: "Here are my financial projections: [paste data]. Write the financial analysis narrative. Explain the key assumptions, translate the ROI into plain language for a non-finance reader, and flag the one sensitivity that could change the outcome most significantly."
Time estimate: Full business case draft excluding financial modeling: 60-90 minutes with Claude. Editing: 45-60 minutes. Versus 2-3 days of drafting and iteration previously.
Before you finalize, ask Claude to stress-test the draft: "Review this business case from the perspective of a CFO who is skeptical of the projected returns. What are the three questions she will ask that this document does not answer? Then add language that addresses each one."
Do the same for other key objections: "From the perspective of an operations leader worried about implementation risk." The prompts make the final document significantly more resilient.