Andon System In Manufacturing: From Cords to Mobile Alerts
The old way was a to signal an occurred problem was a cord or light tower, but the same idea now works through screens, tablets, phones, and real-time machine monitoring. Andon means a preferrably digital signal that shows a production problem needs attention.
A machine stops, a quality issue appears, or an operator needs help. The worst time to discover that problem is after the shift, when the notes are incomplete and the order is already late.
On a mixed-age shop floor, andon does not have to mean new hardware on every machine. The practical 2026 version is simple: your phone, dashboard, and operator screen become the andon system.
This guide covers the full andon family:
Classic signals: cords, lights, light towers, and boards.
Modern alerts: mobile notifications, email alerts, and TV dashboards.
Retrofit use: andon on older machines without replacing working equipment.
Root-cause work: turning the signal into downtime reasons, response data, and OEE improvement.
What does andon mean?
Andon means a visual or digital signal that shows a production problem needs attention.
The idea comes from the Toyota Production System, where andon supports jidoka, often described as stopping production when a problem appears. Operators can call attention to an issue instead of letting defects or downtime move quietly through the line.
In manufacturing, an andon signal can show:
A stopped machine
Missing material
A quality concern
A request for maintenance
A downtime alert on a phone or dashboard
The goal is improvement, not surveillance. A good andon system helps production, maintenance, and supervisors see the same problem at the same time, then fix the cause instead of arguing about what happened later.
The classic andon toolkit
The classic andon toolkit gives production teams a simple way to make problems visible while work is still happening. A cord, light tower, or board turns an operator's observation into a shared signal.
These tools work best when everyone understands what each signal means and what happens next. The goal is faster response, clearer communication, and fewer defects moving downstream.
The andon cord: stopping the line to fix the problem
The andon cord is the classic stop-the-line signal. When an operator sees a quality issue, safety risk, jam, misfeed, or missing part, they pull the cord or press a button.
The signal should mean, "Help is needed here." It should never mean, "Someone made a mistake."
A good cord process usually has 4 steps:
Operator signals the issue: The line stops or slows before more defective parts are produced.
Team lead responds: A supervisor, technician, or support person goes to the station quickly.
Problem gets contained: The team checks affected parts, clears the jam, replaces material, or confirms the safety condition.
Production restarts with context: The reason is recorded so recurring issues can be reviewed later.
The cord gives operators a clear voice in the process. It also protects the line from hiding small problems until they become scrap, rework, or missed output.
Andon lights and light towers: status at a glance
Andon lights show machine or line status from across the floor. A supervisor should be able to look up and know where attention is needed.
A basic light tower might use:
| Color | Typical meaning | Shop floor action |
|---|---|---|
| Green | Running normally | Continue monitoring. |
| Yellow | Help needed or minor interruption | Check the station before the issue grows. |
| Red | Line stopped or critical issue | Respond immediately and contain the problem. |
Light towers still fit well on machines, work cells, packing lines, and areas where operators need a visible local signal. They are especially useful when noise makes spoken updates unreliable.
The key is consistency. If yellow means a material shortage on one line and a quality hold on another, teams will stop trusting the signal.
Andon boards: the shared scoreboard
An andon board shows the wider team what is happening across a line, cell, or department. Instead of one machine status light, the board gives everyone the same production picture.
A useful andon board usually shows:
Current status: Which line is running, waiting, stopped, or under support.
Plan vs actual: Whether the shift is on pace or falling behind target.
Downtime reasons: The reason codes behind stops, not just the lost minutes.
Quality signals: Scrap, rejects, holds, or checks that need attention.
Response ownership: Who is already working on the issue.
The board acts like a shared scoreboard. Operators, supervisors, maintenance, and managers can see the same facts instead of passing updates through memory, paper notes, or end-of-shift reports.
Classic andon tools are simple, but simplicity is their strength. They make abnormal conditions visible fast, which gives the team a better chance to fix the problem at the source.
What andon looks like in 2026
A modern andon system can start without dedicated hardware above the line. The signal can move through devices your team already checks during a shift.
Your phone can be the andon.
When a machine stops or an operator calls for help, the alert should reach the right person before the next walkaround.
A practical 2026 setup often includes:
Mobile alerts: Supervisors and maintenance teams can see stoppages, calls for help, or status changes without walking the floor first.
Email alerts: Managers can receive production updates, reports, or trigger-based notifications when they are away from the line.
TV dashboards: Shop floor screens can show live status, output, downtime, and performance trends so the team sees the same picture.
Operator input: Operators add the reason behind the signal, such as material shortage, tool issue, quality check, or waiting for maintenance.
The goal is fast shared visibility, not surveillance. A good andon process shows where support is needed, helps teams respond earlier, and reveals which losses keep repeating.
Andon on a 20-year-old machine
Older equipment can still be part of a modern andon system. The retrofit job is usually about capturing simple signals from the machine and turning them into useful status.
In plain terms, a sensor or machine signal tells the system whether equipment is running, stopped, counting parts, or changing state. Operator input then adds the reason behind the status.
This works well for mixed-age factories because each machine can be handled according to what it can provide:
Newer machines: Use available machine signals where they exist.
Older machines: Add retrofit sensors or use existing indicators to capture runtime and stoppage.
Manual processes: Let operators send a call for help or log a reason from a tablet, phone, or station.
Shared dashboards: Combine these signals so supervisors see one view across the line.
The first target is usually visibility. Once the team can see runtime, stoppage, and status in real time, the andon process connects more naturally with downtime reasons, maintenance response, and OEE improvement.
GlobalReader fits this approach because it pairs retrofit hardware with cloud software. Factories can start with a few machines, including older assets, and build alerting and dashboard workflows around real production data.
Why andon empowers operators
An andon signal gives the line a voice. When an operator can flag a stop, slowdown, missing material, or quality issue, the problem reaches the right people while work is still happening.
The point is improvement rather than surveillance. Operators already know which machine hesitates, which job causes confusion, and which small interruption never makes the shift report.
A good andon process gives that knowledge a clear path:
Clear permission: Operators can raise a problem without waiting for a manager to notice it.
Faster help: Maintenance, supervisors, or quality teams can respond while the issue is still fresh.
Less blame: The signal focuses attention on the process, not on who happened to be standing nearby.
Better handovers: The next shift sees what happened instead of piecing together the story from memory.
That is why the operator interface matters. Simple prompts, local language, and clear reason codes turn shop floor experience into data the factory can actually use.
From andon signal to root cause
The alert is only the start. A light, screen, or mobile notification tells the team something changed, but root-cause work depends on what gets captured next.
The signal-to-action chain usually looks like this:
Signal: The operator flags a stop, defect, shortage, or unsafe condition as soon as the issue appears.
Reason code: The operator selects the closest downtime reason while the event is still fresh.
Response: The right person gets called to the line with basic context already attached.
Downtime tracking: The system records how long the stop lasted and connects it to the right machine and job.
Analysis: Repeating reasons show where to focus, such as a workstation with frequent technical stops.
This is where andon becomes more than a call for help. When the same reason code keeps appearing, managers can look for the cause instead of debating what happened after the shift ends.
A short stop may point to a worn part, unclear instruction, missing material, or unstable process condition. The andon signal starts the conversation; downtime data shows whether the issue is a one-off or a pattern.
If the pattern affects availability, performance, or quality, connect the analysis back to OEE tracking. That gives improvement work a measurable target, rather than just another list of problems.
FAQ
-
An andon system is the full alert process: signal a problem, notify the right people, and respond fast. An andon board is the shared display that shows machine status, stops, targets, or alerts.
A board is one part of the system. The full system also includes the trigger, the response routine, the reason code, and the follow-up work after the stop.
-
Light towers help when operators and supervisors need machine status visible from a distance. You can also use dashboards, mobile alerts, or operator screens when the goal is faster response, not another physical light.
For mixed-age factories, start with the alert path first. If the right person gets notified quickly, the phone or dashboard can do the same job as a tower.
-
Cost depends on machine count, signal source, dashboard and alert setup, and whether usable hardware already exists. On older machines, software plus simple sensing can often avoid a full light-tower retrofit.
GlobalReader pricing starts from €109/month per machine for the Starter Bundle, which includes hardware, Analytics, Notifications, and Support. Add-ons can be added when the process grows.
-
Andon is about alerting people while a problem is happening. Downtime tracking records the stop, reason, duration, and pattern so teams can fix repeated losses after the shift or during improvement meetings.
Use andon for fast response. Use downtime tracking to learn which stops keep returning, which reasons cost the most time, and which fixes improve OEE.
