Andon (アンドン, あんどん, 行灯) is a manufacturing term referring to a system to notify management, maintenance, and other workers of a quality or process problem. The centrepiece is a signboard incorporating signal lights to indicate which workstation has the problem. The alert can be activated manually by a worker using a pullcord or button, or may be activated automatically by the production equipment itself. The system may include a means to stop production so the issue can be corrected. Some modern alert systems incorporate audio alarms, text, or other displays.
At Toyota, each team member is a quality inspector. At any time during the production process, any team member who spots a problem can stop production by pulling the “andon cord” located next to the assembly line. An andon board (left) lets supervisors know the location of the problem with a blinking light and a distinct musical tone.
An Andon system is one of the principal elements of the Jidoka quality control method pioneered by Toyota as part of the Toyota Production System and therefore now part of the Lean approach. It gives the worker the ability to stop production when a defect is found, and immediately call for assistance. Common reasons for manual activation of the Andon are part shortage, defect created or found, tool malfunction, or the existence of a safety problem. Work is stopped until a solution has been found. The alerts may be logged to a database so that they can be studied as part of a continuous-improvement program.
The system typically indicates where the alert was generated, and may also provide a description of the trouble. Modern Andon systems can include text, graphics, or audio elements. Audio alerts may be done with coded tones, music with different tunes corresponding to the various alerts, or pre-recorded verbal messages.
Liker, Jeffrey (2004) “The Toyota Way” New York:McGraw Hill ISBN 0-07-139231-9