An andon answers one question for anyone walking the floor: which machines need attention right now? The idea is old; what has changed is where the signal comes from.
Where andon comes from
Andon comes from the Toyota Production System, where an operator could pull a cord to signal a problem — and stop the line if needed. It belongs to the principle of jidoka: stop and fix a problem where it happens, rather than pass it down the line. Today the cord is usually a stack light on the machine or a screen on the wall.
What the colours mean
Green
- Usual meaning
- Running normally
Amber / yellow
- Usual meaning
- Needs attention — idle, waiting, or running behind target
Red
- Usual meaning
- Stopped by an alarm or fault
Grey
- Usual meaning
- Offline — no signal from the machine
| Colour | Usual meaning |
|---|---|
| Green | Running normally |
| Amber / yellow | Needs attention — idle, waiting, or running behind target |
| Red | Stopped by an alarm or fault |
| Grey | Offline — no signal from the machine |
The exact scheme matters less than everyone reading it the same way. A board that means something different on each shift gets ignored.
What a useful andon board shows
A stack light shows one machine’s state. A board earns its wall space by adding context: how long a machine has been in that state, and whether it is ahead of or behind the shift’s target.
ThingConnect’s andon board takes each machine’s state straight from its controller — running, idle, alarm or offline — so nobody has to press a button for it to be right. Each tile also shows time in the current state, parts made against target, and time spent in cycle versus handling time. See how it fits with machine monitoring.