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Riskiest Assumption Test Tool
Plan small, cheap tests of the assumptions that would kill your idea, write each pass mark down before the test starts, and judge the results against them.
This tool also runs as a stage in a playbook, which takes you through several tools in order:
- Validate a business idea Stage 4 of 5: is the riskiest assumption true? Start at stage 1
Not following the playbook?
Stage 3 found nothing that would kill the idea, so this tests the biggest unknown. Whether people will pay is almost always a killer: check the ratings there.
What to test
Test the riskiest first. Tests can run at the same time; each keeps its own pass mark.
The test
A click costs people nothing, so it proves little. If you can, ask for money or time.
The pass mark
Write it down before the test starts, and don't move it afterwards.
of them
Already settled by data you hold?
Skip the test only if real data already answers it, such as sales records or supplier prices you have paid. Say what the data is.
Your plans never leave your browser
The assumptions, plans and your notes stay on your computer and in your progress file. To write the diagnosis, only the numbers, such as each pass mark and result, are sent to our server. How it works
Record the results
Record each result when it is in. A test still running can stay empty.
Two numbers for the next stage
From the test, not from hope. Stage 5 uses them to check break-even.
The tests, written down before they started
Save your progress
Download your progress file to continue from this point any time, on any computer: choose it under "Coming back?" at the start of the tool. Each new file includes everything so far, including the earlier stages when they are connected, so keep the latest one. Your work stays in this browser only until you close it.
Not saved yet.
Take your results with you
A PDF of each test as it was written down, its result against the pass mark, and the verdict.
About the tool
Why it exists
No framework can tell you whether people will pay
Only a test can. The riskiest assumption is the one that would kill the idea if it were wrong and that you are least sure of. Some are about demand: will people pay, and how? Others are about delivery: can you do it, at a cost you can live with? Each gets the smallest, cheapest test that could prove it wrong, often doing the service by hand for a few customers before building anything.
Write each pass mark down before the test starts, and don't move it afterwards. A result judged after the fact can always be made to look like a success. This tool works on its own, and as stage 4 of our playbook for validating a business idea, where the assumptions come from the Lean Canvas in stage 3.
The method
How the tool works
What to test. In the playbook, the list starts with the assumption stage 3 chose, then every other one that would kill the idea and that you are not sure of, in rank order. You can add others. Tests can run one after another or at the same time; one trial can check two assumptions, each with its own pass mark.
Two kinds of test. "Will people do it?" counts how many commit something real: money, time, or only a click, which is the weakest. "Can we do it, at this cost?" measures a number against a limit, such as the cost of serving each customer. The tool suggests a plan for the empty fields from what it knows, including a starting pass mark of about 60%; the pass mark is yours to set.
The pass mark, written down. Locking it records the date. You can still change it, but the change is recorded, shown in the report, and the test is judged against the mark you wrote down first. A test can be skipped only when data you already hold settles it, and the report says so.
The verdict. Passed when the count reaches the mark, or the number is within the limit; just short when within one person or 80% of a count, or 10% of a limit; otherwise failed. If the riskiest fails, change the idea and test again, or stop.
What leaves your computer. The assumptions, plans and notes stay in your browser and your progress file. To write the diagnosis, the page sends our server only the numbers, and the server keeps nothing.