# Andon

**URL:** https://kaizumi.com/dictionary/andon

**Description:** Andon is a visual signaling system that alerts teams to problems, status changes, or requests for assistance in real time.

**Japanese:** 行灯 (andon) — "paper lantern, signal light"

**Category:** lean-tools

**Tags:** visual-management, quality

## Definition

Andon is a visual management system that displays real-time status and alerts teams to abnormal conditions. Originating from Toyota, where lights on the assembly line indicate status (green for normal, yellow for caution, red for stopped), andon can be lights, displays, sounds, or digital dashboards. When workers encounter problems—quality issues, shortages, safety concerns—they activate andon to summon help. This makes problems visible immediately, enables rapid response, and prevents defects from moving downstream. Andon embodies the principle that problems should be exposed, not hidden. See an andon pull from cord to team-leader response to the painted fixed-position line in the [interactive Toyota assembly guide](/guides/toyota-assembly).

## Examples

### Manufacturing

> Each assembly station has an andon cord. When operators encounter problems—missing parts, quality issues, unclear instructions—they pull the cord. The andon light activates, music plays to identify the location, and a team leader has 60 seconds to respond before the line stops. This system catches problems at the source.

### Healthcare

> A hospital uses andon principles through call lights, bed alarms, and real-time dashboards showing patient status by room. When a patient activates a call light, staff respond immediately. Escalation protocols engage additional resources if initial response is delayed.

### Administrative

> A service center uses digital andon—real-time dashboards showing queue status, wait times, and service level. When metrics turn yellow or red, supervisors are alerted to take action: reassigning staff, activating backup resources, or adjusting priorities.

## Key Points

- Andon makes problems visible in real time, enabling immediate response
- Activating andon should be expected and supported, not criticized
- Response protocols determine what happens when andon is activated
- Andon data reveals problem patterns and improvement opportunities

## Common Misconceptions

**Andon is just a signal light.** Andon is a system—not just the signal but the response protocols, the culture of stopping for problems, and the management support that makes it work.

**Stopping the line for problems reduces output.** Short-term interruptions prevent larger problems downstream. The total cost of immediate response is far less than the cost of defects escaping to later processes or customers.

## Watch It Happen

The second half of andon is the part that gets skipped. In the factory simulation a beacon goes up at a station and a team leader in hi-vis walks over from the hour-by-hour board to work the problem with the operator. The line does not restart on a timer — it restarts when the two of them have actually fixed something. An andon that summons nobody is just a lamp.

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## See Also

- [Jidoka](/dictionary/jidoka) - The principle andon supports

Source: https://kaizumi.com/dictionary/andon
Licence: free to quote and cite with attribution to Kaizumi.