Approach to product design that is iterative, depends on short development cycles, and views product / feature creation as a bottom-up response to obstacles that arise when customers use the product rather than a top-down implementation of a long-term plan.
” In the Lean Startup model, we are rehabilitating learning with a concept I call validated learning. Validated learning is not after-the-fact rationalization or a good story designed to hide failure. It is a rigorous method for demonstrating progress when one is embedded in the soil of extreme uncertainty in which startups grow. Validated learning is the process of demonstrating empirically that a team has discovered valuable truths about a startup’s present and future business prospects. It is more concrete, more accurate, and faster than market forecasting or classical business planning. It is the principal antidote to the lethal problem of achieving failure: successfully executing a plan that leads nowhere.” (38, Lean Startup)
Lean Startup by Eric Ries