Prozanta Template
Andon system design
Visual signalling and an escalation protocol for deviations
Production line:
Department:
Version / Date:
How to use this template
Andon (Japanese: "lantern") is a visual signalling system that makes deviations visible instantly — to the operator, the team leader and the manager. The core principle from Toyota: stop and solve the problem now, rather than producing defects on to the next station. This template helps you design your own Andon system and define clear reaction rules.
GREEN
Normal operation — nothing needs attention. The system runs to plan.
YELLOW
Attention — help needed within 2 min. Production can continue briefly.
RED
Stop — production stopped immediately. Escalate now. No production until the problem is identified.
Step by step — design your Andon system
- Fill in the signal-definition table: what triggers each signal on this specific line?
- Define the maximum response time per signal — YELLOW typically 2 min, RED 0 min (stop immediately).
- Decide the escalation sequence: operator → team leader → operations manager → head — with a time limit at each level.
- Train all operators and team leaders — Andon only works if everyone takes it seriously.
- Use the incident log weekly to identify recurring problems and open an A3 or 5 Why.
Watch out
- If Andon signals never lead to action, people stop activating them — the manager must always follow up.
- Too many YELLOW signals per day (over 10) indicates an unstable process — focus on the underlying cause.
- A BLUE signal is used for planned stops (maintenance, changeover) — separate it clearly from fault situations.
Example
- YELLOW signal: the operator is out of parts for the next batch. The team leader reacts within 2 min, confirms remaining-stock status.
- RED signal: machine temperature exceeds the limit — production is stopped, maintenance is called, all parts since the last check are quarantined.
Method: Toyota Production System "Jidoka" (autonomation); cf. Shigeo Shingo and the Toyota standards for stop-line authority.
Signal definitions for this line
| Signal | Trigger criterion (when activated) | Who reacts | Max response | First action |
|---|---|---|---|---|
| 🟡 YELLOW | min | |||
| 🟡 YELLOW | min | |||
| 🔴 RED | min | |||
| 🔴 RED | min | |||
| 🔴 RED | min | |||
| 🔵 BLUE | min |
🔵 BLUE = planned maintenance / changeover — not a fault
Escalation protocol for a RED signal
Operator activates the andon
Stop the machine. Mark defective parts. Note the start time.
Owner: Actual time:
Team leader arrives
Assess the situation. Can it be solved? → Solve and restart. Cannot? → Escalate to level 2.
Owner: Actual time:
Operations manager called in
Resources and decision authority. RCA started. Delivery reassessed.
Owner: Actual time:
Head informed
Only for stops that threaten customers or safety. Written report by EOD at the latest.
Owner: Actual time:
Andon incident log — weekly overview
| Date/time | Signal | Cause | Downtime (min) | Solution | Repeat? |
|---|---|---|---|---|---|
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Andon system design
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