Andon

See also Visual Factory and 5S Workplace Organization

You have probably heard of andon cords, andon boards, andon lights, etc. Andon is a Japanese word, which means “lantern” or “lamp”. Lanterns have been used for signaling purposes in many cultures throughout history (does “one if by land, two if by sea” ring a bell?). Toyota adopted the term to describe a system for signaling the appropriate individuals regarding the status of a given process.

The purpose of an andon signal (in whatever form) is to bring attention to a quality or process problem. On the Toyota production line, if an operator has a problem, he/she pulls the andon cord to signal that help is needed. Pulling the cord lights up an indicator on the andon board and starts playing a particular musical tune (the particular tune indicates the trouble area). These indicators make it very clear that help is needed in a particular location – the andon board sometimes also indicates the type of help needed (maintenance, team leader, supplier, etc.) Andon boards can be in the form of computer screens, paper charts, electronic boards, manual boards, etc. They often include lights and/or sounds to communicate the status of a process and to call for help.

The underlying principle and purpose of andon is to have an unambiguous mechanism for continually making the status of a particular process clear to everybody. In a factory, the andon board is located where it can be clearly seen (often, in many locations). For remote locations, the andon board would typically be in a computer, and networked to everybody who needed to be aware of the status of the processes at that location. Once

again, the purpose for andon devices/mechanisms is to indicate the status of a particular process.

Note: Andon can easily be confused with kanban since they both represent a mechanism for signaling. Their distinction lies in the purpose for the signal.

Andon is a mechanism for signaling that a quality or process problem exists in a particular process (or, the status of the process).

Kanban is a mechanism for signaling the need for replenishment of materials or supplies, or a need for information.