In the words of the late Kiichiro Toyoda, former President of Toyota, in an industrial enterprise such as automobile assembly it is best for parts to arrive at line side “Just In Time”.

This theory is well known, but when you actually try to practice this you run into various problems, and it is not easy to do. If you say “Just In Time is an ideal” or “Just In Time is not realistic” then that is the end of the story.

To common sense thinking it seems that Just In Time is full of contradictions, such as that between Just In Time and productivity, or between Just In Time and cost, or even the squeeze Just In Time puts on suppliers.

We must break through this wall of common sense, and go “beyond common sense” in order to take the two contradictory sides and make them stand up to reason.

“Just In Time” translated to the language of the gemba is “(The departments that need) go to get what they want, when they need it, in the amount they need.”

The downstream process goes to the upstream process to get it. In the case of supplier parts they must deliver, so we specify the quantity, date and time of deliveries.

This is the basic thinking of the Toyota Production System, and it was this thinking that was developed and made concrete in various ways.

The upstream process must be able to produce in response to this more economically. It is too easy for the upstream process (manufacturing shop floor) to think of quality, quantity and cost as separate things. The focus may be on quality, or meeting production volume, or even cost. Often there is a particular focus on quantity.

I used to call the technique of harmonizing quality, quantity and cost “gemba technique”. Some also call this “manufacturing technique”.

I recently had the opportunity to coin a new name for “Toyota-style IE”, which I called MIE for “moukeru IE” [translation note: moukeru = 'to make a profit' in Japanese]. The name aside, our system is so far from generally accepted ideas (common sense) that if you do it only half way it can actually make things worse.

If you are going to do TPS you must do it all the way. You also need to change the way you think. You also need to change how you look at things.

Just as magicians have their tricks, the gemba technique has its tricks. The magician’s trick in this case is “the relentless elimination of waste”. In order to eliminate waste, you must develop eyes to see waste, and think of how you can eliminate the wastes you see. And we must repeat this process.