Giving machines and operators the ability to signal when an abnormal situation occurs and stop work immediately. This makes it possible to build quality into any process and separate the tasks of people and machines, allowing for more efficient work. 

Jidoka is one of the two pillars of the Toyota Production System; the other pillar is Just-in-Time. 

Jidoka draws attention to the causes of problems; work is stopped immediately when a problem first occurs. This leads to improvements in processes by eliminating the root causes of defects. 

Jidoka is also sometimes called autonomization , automation with human intelligence. In effect, equipment gains the ability to autonomously distinguish good parts from bad, without the need for an operator to oversee it. This eliminates the need for operators to constantly monitor machines, resulting in great productivity gains by allowing one operator to operate several machines. This is also known as multiprocess handling

The term jidoka dates back to the early 20th century, when Sakichi Toyoda, the founder of the Toyota Group, invented a loom that automatically stopped when the thread broke. Previously, looms produced mountains of defective fabric after a thread broke, so each machine had to be watched by an operator. Thanks to Toyoda's innovation, only one operator was needed to monitor several machines. In Japanese, jidoka is a Toyota-created term pronounced exactly the same (and written almost the same in kanji) as the Japanese term for automation, but with the added connotations of humanity and value creation. 

The evolution to jidoka:

Manually load and watch while machine does its work
Watching while machine does its work
Machine that monitors itself

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