The central aspect of “lean thinking” is the identification and fulfillment of customers’ needs, because in the end the customer decides how good a process really is. After all, it is the recipients or customers of your goods, services and information who can really assess the extent to which you deliver the right thing with the right quality, at the right time, in the right form. Therefore you should constantly question and optimize its fulfillment.
Thus Taiichi Ohno derives from the question “What is the customer willing to pay for” that there is too much waste in the regeneration process, which does not add value to the customer. Therefore his goal was to optimize the entire process between placing the order and receiving money.