Lean Manufacturing

What is Jidoka? Test Drive a Minivan

By Jon Miller Published on January 14th, 2004

I will confess, we own a minivan and I enjoy driving it. It’s a great car. If I wasn’t already a fan of Toyota products and how they make them, the Sienna would certainly make me a fan.
As a Lean guy, I particularly like how they have incorporated Jidoka into the design of their vehicle. For review, Jidoka is a Japanese word meaning autonomation or intelligent automation. Jidoka is one of the two pillars of the House of the Toyota Production System (the other pillar is Just in Time). There are two parts to Jidoka.
First, in Jidoka there is a seven step process for low cost automation that results in a clear separation of human work and machine work. Although we would never watch a washing machine run, many machinists will watch a CNC machine running parts. Jidoka make it possible to load a machine and walk away to run another machine. This load-load concept (also known as chaku-chaku in Japanese) allows not only multi-machine handling but multi-process handling, enabling one piece flow machining. Being able to load and walk away improves productivity as a machinist can become a multi-process handler, as well as improving safety since you are not near the machine should there be a machine dangerous malfunction.
Second, in Jidoka the ability to automatically detect errors and stop is built into the machine. Unlike “dumb” automation that keeps stamping out bad parts until the inspector comes along and rejects the whole batch, a Jidoka machine will sense an abnormal vibration, noise, heat, or other signal, stop the process and alert the operator. This has the effect of drastically reducing defects.
So what does this have to do with the Sienna? Toyota has made the right side rear door auto-opening and auto-closing. Just lift the door handle, and the door opens or closes. Load the baby in the car seat, give the handle a gentle pull, and walk away to the driver’s seat while the door closes by itself. Human work and machine work are separated.
One of my initial concerns was that someone would get an arm or leg caught in the door as it closed mechanically. This concern was put to rest when the salesman at the car dealership demonstrated by putting his arm in the way of the closing door. The door sensed an object in the way, stopped and reversed itself. The door detects an error and auto-stops.
This is an example of Lean thinking in the design of a product. I’m looking forward to Single Minute Exchange of Tires.

  1. Boris

    March 24, 2004 - 5:29 am

    Thanks for your article – this brief summary was exactly what i hoped to find whne looking for an explnation of jidoka

  2. Jeff

    June 27, 2004 - 7:53 pm

    It seems we talk so much about Lean and Japanese companies — the example given in this article of the auto opening/closing minivan door was introduced into the market by General Motors.

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