As we look at the House of Lean, we tend to concentrate on the Foundation and JIT pillar. I’d like to write today about the other pillar – Jidoka for without it, our House of Lean would tilt and the roof would surely come crashing down.
Jidoka or autonomation as it is often translated to, really refers to “Built in Quality at the Source” or even more simply – Don’t pass defects on. Many people forget that high quality and Just In Time go hand in hand. There’s no sense reducing lead times just to move defects faster through the value stream.
I like to think of Jidoka as three things:
- Don’t accept defects
- Don’t make defects
- Don’t pass defects on
The origins of Jidoka go back to the original Toyoda (correct spelling of the family name) family Weaving Loom business. Before they became famous for making automobiles, the family was in the business of making weaving looms that had a reputation for making cloth of very high quality levels.
In the late nineteenth century, people used to sit and watch the weaving machines make cloth waiting for any broken threads which would lead to defects in the cloth. When they saw a broken thread they would stop the machine, repair the thread and restart the machine. Imagine a job like this, watching a machine do the work and reacting only when there was a problem. What a waste.
Toyoda saw this and invented a method whereby the weaving loom would self-detect a break in the thread, stop and alert the operators. The operators could then repair the thread and restart the weaving loom. Now one person could operate many looms and the looms would produce only cloth of the highest quality.
This is where the term Jidoka came from. Autonomation – automation or machines but with a human touch. Ones that can self-detect errors, stop and alert the operator. Now machines can do what they do best which is detecting defects and humans can do what they do best which is problems solving.
By implementing Jidoka, we implement a system that prevents defects from being sent to the next person or operation in the value stream. Now we can begin to introduce JIT and cash in the benefits of reduced inventory and lead time.
Jidoka and JIT – we need both pillars to be working hand in hand to truly provide value to our Customers.