Jidoka

Highlighting/visualisation of problems - Quality must be built in during the manufacturing process.

If equipment malfunction or a defective part is discovered, the affected machine automatically stops and operators cease production to correct the problem.

For the just in time system to function, all of the parts that are made and supplied must meet predetermined quality standards. This is achieved through jidoka.

Jidoka means that a machine safely stops when the normal processing is completed. It also means that, should a quality/equipment problem arise, the machine detects any problem on its own and stops, preventing defective products from being produced. As a result, only products satisfying quality standards will be passed onto the following processes on the production line.

Since a machine automatically stops when processing is completed or when a problem arises and is communicated via the “andon” (problem display board), operators can confidently continue performing work at another machine, as well as easily identify the problem's cause to prevent its recurrence. This means that each operator can be in charge of many machines, resulting in higher productivity, while continuous improvements lead to greater processing capacity.