
Key takeaways
Short answer: An andon system is the operator-driven signaling framework that surfaces abnormalities. Effective andon design makes signaling easy, escalates quickly, never punishes the signaler, and tracks response time as the health metric. Most andon systems decay because operators stop signaling — usually because of slow response, perceived punishment, or no follow-up. Designing against those three failure modes is the work. See also Andon Cord vs Andon Light.
All five are necessary. Missing any one breaks the system.
Two states minimum, often three:
Some plants add additional codes (blue for material, white for maintenance). Each additional code dilutes attention; resist proliferation.
Two principles:
Digital triggers in OEE platforms work, but they should not require login or navigation. One tap.
What happens when yellow goes on:
Numbers vary by plant. The principle: escalation is automatic, not dependent on operator follow-up.
Response means going to the line, observing, helping. Not opening a meeting room. The response is at the workstation, with the operator.
Response time is the health metric. Track it. Display it. Make it visible.
The single most important andon design rule: never punish operators for signaling. The moment they perceive punishment for raising yellow or red, signaling drops to zero and the system dies.
This is hard culturally. Production pressure naturally creates frustration with stops. Leadership must protect the signal explicitly.
1. Slow response. Yellow signals are ignored or take 10 minutes to respond. Operators stop signaling.
2. Punishment. Operators who trigger red get questioned aggressively. Future signals avoided.
3. No follow-up. Resolved at the moment but root cause never addressed. Same issue recurs.
4. Cluttered triggers. Too many color codes operators have to choose between. Defaults to "yellow" or "other."
5. No metric on response time. Health invisible until adoption collapses.
Every red signal is an Availability loss with a captured reason code. Every yellow is a Performance loss (line slowed during help). The data flows into the OEE Pareto.
Plants integrating andon with OEE see cleaner downtime reason-code data than plants that try to capture reasons after the fact.
1. Andon without escalation. Signal exists; nobody responds.
2. Andon punished implicitly. "Why did you stop the line?" said the wrong way kills future signals.
3. Color proliferation. 8 colors with different meanings. Nobody remembers them.
4. No data trail. Signals happen; no record. Cannot improve.
A modern OEE platform supports digital andon triggers, automated escalation routing, response-time capture, and integration with reason-coded downtime in OEE Pareto.
Fabrico's OEE module includes operator-side andon triggers with escalation routing, response-time capture, and direct integration into OEE Pareto with reason codes.
See how Fabrico captures this automatically — explore OEE for manufacturing or book a demo.
Yellow: under 60 seconds. Red: under 30 seconds.
Three (green, yellow, red) is the standard. Adding more dilutes.
In high-mix or high-quality-risk operations, yes. In simple operations, line-level may be enough.
Partly. Physical lights work without power or screens. Software complements with data capture.
Punishing the signal. Once operators feel punished, they stop signaling and the system dies.