5 Whys A method to easily get to the heart of the message you want to communicate: the 5-Why method. 5 Whys - What? It originally comes from quality management and is an instrument for determining cause and effect. Toyoda Sakichi is considered the father of this method. He was a great inventor and founder of Toyota Industries Corporation, Ltd. His main message is as follows: If a problem arises, ask "why?" five times in order to identify the cause. Then change the production