In my Toyota interviews, when I asked what distinguishes the Toyota Way from other management approaches, the most common first response was genchi gembutsuwhether 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 Lean Startup by Eric Ries