Changing the die - that can't go faster

Posted by Marcus Hammarberg on August 7, 2017

This summer I decided to read The Machine that change the world. This a must-read for every Lean aficionado and the book that first coined the term in the first place.

It was very interesting to see the authors utter fascination of the ways of the Japanese car manufacturer, much of which was the opposite of whatever was the de facto standard for mass production at the time.

My favourite part was the history of car manufacturing that and how the Toyota Production system grew came out of necessity in a country that, at the time, was way behind and with little resources as well as little buying power.

There’s an awesome little paragraph in the book (page 51-52) showing clearly how Taiichi Ohno (and in turn Toyota) let their strive for a faster flow change things that was considered constants.

At the time (and still I presume) you make cars from a roll of steel that then is stamped into the required parts for the model needed. These dies of course need to be very heavy and sturdy since you, quite literally, are stamping things out of steel. Also they need to be extremely precise as smallest problem would replicate throughout all the parts stamped out.

Changing a die to stamp out another part was very time consuming and hard work. It took a full day to change them and that was considered a constant.

Now with the focus of higher flow and flexibility, required by the limited buying power and demands in the Japanese market - a day to be able to change die was not enough. So with relentless, and typical Japanese/Toyota, dedication Mr Ohno started to improve the change mechanism.

After 20 years (!) it was down to just 3 minutes. Toyota could now easily switch dies back and forth to fast and smoothly create the particular car parts required. The batch size and inventory was kept to a minimum while flow was intact.


First of all it’s interesting to see that the rest of the car industry considered changing the die a time constant. It took 12 hours. There are so many things in our industry (IT) that was considered a fact a few years ago that now is done radically different, or now at all. On the top of my head:

  • Administration of servers to cloud to serverless
  • Manual regression testing to unit tests to automated end-to-end testing (on a server farm that we don’t manage)
  • People from a special branch deploying our application to continuous delivery
  • Big project that many people was administrating to agile autonomous teams

We have to continue to challenge the current ways to become better.

The second observation is that one of the reasons that Taichii Ohno pressed on was that he had a strong guiding star; smaller batches with less inventory. This is famously summarised in Toyota production strategy:

One piece continuous flow

Armed with that he pressed on through, what I can only imagine, must have been an endless line of “We can’t do that here”.

Now… is the North Star of my company known? Do I use it to challenge the status quo and accepted truths in our business.

I was very inspired to keep challenging the current ways in my job, in our industry. Who knows what we take for granted today that we will look back on as an old practice later?

Published by Marcus Hammarberg on Last updated