Which three-word cycle is central to Eric Ries’s lean startup method?

Eric Ries’s lean startup method centers on the three-word cycle “build-measure-learn.”

The cycle describes a disciplined way to develop products under uncertainty. A startup first builds a version of an idea, measures how customers respond, and learns whether to continue, change direction, or refine the offering. The process is intended to shorten development loops and replace assumptions with evidence.

The method grew from Ries’s experiences with failed and developing technology ventures and from ideas associated with Steve Blank’s customer-development approach. It does not mean that startups should avoid planning or long-term vision. Instead, it encourages testing the riskiest assumptions early and repeatedly.

A common mix-up is treating the phrase as a generic slogan for experimentation. In lean startup writing, it is specifically a feedback loop: the product creates data, the data informs learning, and that learning determines what the team builds next.