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Stress test a business plan before you commit money
Give it the plan. Get a one-page canvas, the strongest case against it, stress-tested assumptions and a pre-mortem.
Stress test a business plan before you commit money is a free AI workflow for the job "Test an idea before you build it". It guides your AI through several skills in order, passing each step's output to the next.
Free · No account · Made by AI Blocks · Thinking: high
What it does
A business plan is written to persuade, which makes it the worst document for finding its own flaws. The assumptions are buried in the forecast and the one risk that could end the company is a line in a list of twenty. This workflow attacks the plan on purpose. It first squeezes the plan onto a one-page canvas so every assumption is visible. It writes the strongest honest case for killing the idea. It stress tests each assumption: what if it is half as good, what if it takes twice as long. It then checks for risks of ruin, in Nassim Taleb's manner: the ones you cannot recover from. Last it runs a pre-mortem: it imagines the plan has failed a year from now and writes the most likely story of why, so you can fix that story before it happens.
You give it
- The business plan, however rough
- The numbers behind it: costs, prices, how many customers and when
- What you are putting in: money, time, what you give up
- What you fear most (optional)
You get
- A one-page canvas with every assumption visible
- The strongest case for killing the idea
- Each assumption stress tested at half as good and twice as slow, and a ruin-risk check
- A pre-mortem: the most likely story of failure and what to change now
Use it when
- You are about to sign a lease, hire or spend savings on a plan.
- Everyone around you likes the plan, which worries you.
- A past plan failed for a reason that was obvious afterwards.
Steps
- Lean canvas builder: Describe your idea. Get a one-page lean canvas with problem, solution, channels, costs and revenue.
- Business idea killer: Give it a business idea. Get the one fact that kills it, or the cheapest test it still has to pass.
- Business assumption stress tester: Give it a plan and its key bets. Find which assumptions break first and what to test.
- Ruin risk stress tester: Paste a plan with money, time or your name at stake. Get the outcome that could ruin it and a capped-downside version.
- Plan pre-mortem runner: Give it a plan. Imagine it failed in a year and get the hidden assumptions and risks found now.
How to use it
- Download the handoff pack. It's a zip with HANDOFF.md and every skill file this workflow uses.
- Give the folder to Claude (in Claude Code, or as files in a Claude Project) and say "Follow HANDOFF.md".
- Paste the plan and the numbers. It writes the canvas and the case against.
- Read the stress tests and the ruin risks. Decide which you can remove.
- Read the pre-mortem. Change the plan so that story cannot happen, or decide not to go.