The central aspect of "Lean Thinking" is the identification and fulfillment of customer added value, because how good a process is is always decided by the customer in the end. Because it is the recipients or buyers of your goods, services and information who can really judge the extent to which you deliver the right thing in the right quality, at the right time, in the right form. Therefore, you should constantly question and optimize its fulfillment.
Therefore, Taiichi Ohno deduces from the question "What is the customer willing to pay for?" that there is too much waste in the creation process that does not provide the customer with added value. Therefore, his goal was to optimize the entire process between placing the order and receiving the money.