What is Key Assumption?
A belief your plan depends on that would change the roadmap if it proved wrong, such as how capable the next model will be. Name a few for the next three to six months and recheck them every month.

1 bearing · checked monthly · holds
A key assumption is…
Write it in your own words in the app.
In real work
The PM wrote down the key assumption under the agent roadmap, that models will close full refund cases without a handoff by spring, and rechecks it each month.
In the illustration
The whole deck rests on one bearing. Each month an inspector reads the dial indicator on it; this month the needle sits inside the green band, so the deck stays as planned.
In your model, list each key assumption behind the roadmap below: the belief, the date we recheck it, the evidence that would prove it wrong, and which bets change if it does.
Try it now
The fastest way to learn a word is to use it. Open this line in the agent you already work in and watch what it does. Change the tool to the one you use.
Go further
01Practice
Make it stick
One term a day, a short quiz, and sentence practice that checks your own words.
02Verify
Prove you know it
Pass the quiz and keep it in a Skills Wallet you can share with anyone who needs proof.
03Career
Find the work that uses it
See which roles lean on this vocabulary, and what they pay in year one.





