This is one of the most important lessons of the scientific method: if you cannot fail, you cannot learn. - Eric Ries

if you cannot fail, you cannot learn.

We must learn what customers really want, not what they say they want or what we think they should want.

In my Toyota interviews, when I asked what distinguishes the Toyota Way from other management approaches, the most common first response was genchi gembutsu — whether I was in manufacturing, product development, sales, distribution, or public affairs. You cannot be sure you really understand any part of any business problem unless you go and see for yourself firsthand. It is unacceptable to take anything for granted or to rely on the reports of others.

The true measure of runway is how many pivots a startup has left: the number of opportunities it has to make a fundamental change to its business strategy. Measuring runway through the lens of pivots rather than that of time suggests another way to extend that runway: get to each pivot faster. In other words, the startup has to find ways to achieve the same amount of validated learning at lower cost or in a shorter time. All the techniques in the Lean Startup model that have been discussed so far have this as their overarching goal.