Andon is a crucial part for the visual management on the shop floor that gives a signal that indicates if and where there is a problem. Typically indicated with a traffic light signal red = failure mode, yellow = non-conforming performance and green = normal operation mode.
The methodology of Andon as part of the shop floor management, is to show the current operating status of a machine or a production line in a way that everyone can see and understand it immediately. As typically in Lean Terms Andon comes from the Japanese language and means paper lamp or just lamp.
Going along the Andon-Systematic there is to mention the Andon-Cords. The cords are used by operators to activate the lamps by either tear the cord or more likely nowadays pressing the corresponding buttons, which are attached above the production line and are easily accessible for the operators hanging downwards or as button attached at the work station.
If a non-conforming condition occurs, the yellow Andon signal initiates the support so that the problem that has occurred can be remedied immediately with additional supportive functions, such as maintenance. In worst case it is also possible to stop the complete production (red signal) until the problem has been solved or at least suitable countermeasures are in place.
An Andon has three main functions:
- Visualization of the operating status of a machine/assembly line
- Possibility for the operator to report an non-conforming condition and escalate it using a defined escalation process
- Production or belt stop, so that no non-conforming products or components are passed on to the next process step
The clear display of the operating states of several workstations was used quite early in the development of the Andon systems. The godfather of the TPS, Taiichi Ohno once described it as followed: “When one looks up, the andon (the line stop indication board) comes into view, showing the location and nature of trouble situations at a glance.”
In the course of time, the Andon board has increasingly developed into an information board for all employees involved in the process. They display status information regarding the current situation in production, such as the number of units produced per day or per hour, the degree of delivery reliability to the customer or the cumulated amount of backlog. In this way, all process participants are aware of the current situation and can act accordingly.
