Whether a sale can actually happen yet, which is a different question from whether your work is finished.
Example
Marcus has tested six candle scents and printed labels, but never decided a price. A customer asks how much, he guesses low, and loses money all day. His candles were nearly perfect and he was not ready.
How it fits in
Five checks decide readiness: there is a version someone could buy this week, you know the one place you will be, the price is already decided, you can say what it is in one sentence, and you could deliver if several people said yes. Missing polish is never a reason to wait. Missing a price or missing stock always is, because those stop a sale from physically completing.
Where this is taught
Related terms
A small specific rule of the shape 'if X happens, then I will do Y'. Specific beats vague almost every time.
Work in focused 25-minute blocks with a five-minute break in between.
If a task takes less than two minutes, do it now. The hassle of putting it off costs more than the task itself.