Ohno decided there was no reason other than inefficiency and wastefulness why Toyota's productivity should be any lower than that of Detroit. Hence he set out to eradicate inefficiency and eliminate waste in the part of the production process that he was responsible for. This became the core of the so-called Toyota Production System (TPS) that he and others subsequently developed between the mid-1940s and the mid-1970s. Several elements of this system have become familiar in the West: for example, muda (the elimination of waste), jidoka (the injection of quality) and kanban (the tags used as part of a system of just-in-time stock control).