"Asking why all the time is the most effect route to overcoming problems. "The only drawback to it Iʼve found is when youʼve needed only three whys to get to the root cause, some determined people still go on to ask two more. Or else they stop at the fifth, even if they havenʼt gotten to the root cause... Blinded by the quality tools and techniques, you have missed the completely obvious"
