A “Visual Control” device that indicates the “Status” of a machine, line, or process. Frequently audible alarms or warning messages accompany ANDON status lights as a secondary method of communicating a problem has arisen.

ANDONS are typically color-coded with these generic colors:

Green (Normal Operations)

Yellow (It is time for a changeover or planned maintenance)

Red (A problem has occurred, the machine or line is “DOWN,” and “Urgent attention is needed.

Comments: As Lean practitioners we have seen ANDON lights and warning sounds be very effective in certain settings and within a disciplined Lean culture. Conversely, we have seen them very much ignored and therefore disconnected due to their annoying qualities and lack of discipline.

ANDON’s can be very effective in highly automated processes to alert support personnel of problems who must attend to several automated processes at a time or are not located in close proximity to the machines they oversee.