Jidoka

Jidoka (literally translated) means "Automation".  Through shop usage at Toyota the word has taken on other connotations. One meaning refers to the stopping of a manual assembly or production line when something goes amiss.

At Toyota, every worker has the authority and the responsibility to stop an entire line when a problem arises. The purpose is to bring attention to the problem, regardless of how small, and focus efforts on it. This forces a permanent  solution. 

It has been an article of faith in automotive plants that an assembly line must never stop. When Taiichi Ohno first told supervisors to stop the lines when trouble developed, they were incredulous.  

At first, the line that stopped frequently had lower output. After several months, however, the situation reversed. The line that rarely stopped still had the same problems. These problems stalled productivity improvements and created rework that lowered efficiency. The line that initially saw frequent stoppages found that the stoppages had been reduced and overall efficiency improved.

A Cautionary Note

Jidoka only works when the supervisors and operators have the skills and experience to fix the problems. Jidoka, itself, only spotlights the waste. 

Employees should have at least twelve hours of training in Root Cause Analysis, four hours in Process Mapping and six months of intensive practice before Jidoka is employed.

References

MONDEN, YASUHIRO, Toyota Production System, Third Edition, Industrial Engineering & Management Press, Atlanta, Georgia, USA, 1998.

HARRIMAN, FRED, http://www.fredharriman.com/resources/documents/FHcom_Kaizen_Terminology_03.pdf, 2000.

OHNO, TAIICHI, Toyota Production System- Beyond Large Scale Production, Productivity Press, 1988.