Summary :

The andon is not just a simple screen: it is a system that combines reliable detection, immediate visibility, and structured response. In machining, the andon fails when it is reduced to green or red boxes, without context or escalation rules.

A truly useful andon allows you to understand what is happening, assess the severity of a situation, and quickly identify who needs to intervene. Its ROI lies in reducing response time to stops, often faster than a traditional Lean project.

En d'autres termes, Landon est un système Lean qui rend un problème visible dès qu'il apparaît et déclenche une réaction rapide. Un andon efficace combine état machine, contexte et escalade pour réduire le temps de réaction aux arrêts et stabiliser la production.

The Andon, a symbol of Lean rarely well applied in machining

Andon is one of the best-known symbols of Lean. In manufacturing, it immediately conveys a simple idea: make problems visible as soon as they occur and trigger a rapid response. In assembly environments, Andon has become almost a standard. A workstation stops, a signal is triggered, support responds, and the line quickly returns to its normal pace.

In machining workshops, the reality is different. Andon is far less common, and when it is implemented, it is often underutilized. In some cases, it is reduced to a screen displaying machine status in green or red, without any real intervention logic behind it. In others, it is perceived as a monitoring tool rather than a driver of continuous improvement.

However, the machining is an ideal ground for a modern andon, provided it is approached correctly. In a workshop where performance heavily depends on machine availability, cycle stability, and response speed to stoppages, the andon can become an extremely powerful. The key is to understand what a truly useful andon is, why it often fails in machining, and how to design it to reduce response time to stoppages. 

The andon is not a screen: it is a reaction system

An andon is not just a display. It is not a light board, nor an interface that colors machines green or red. An andon is a complete system that combines three inseparable elements: the detection of a deviation, the immediate visibility of that deviation, and a structured response.

Without a response, an Andon system becomes nothing more than decoration.

Without visibility, an Andon system becomes ineffective.

Without reliable detection, an Andon system becomes noisy or misleading.

In a machining workshop, an Andon system must serve a very practical operational purpose: enabling the production team to immediately know where the problem is, what it means, and who needs to respond.

This organizational dimension is often overlooked. Many companies deploy a visual display but fail to implement the response system behind it. As a result, they end up with a monitoring screen—not an Andon system.

Why andon is rarely deployed in machining

If the andon is so well-known in Lean, why is it so rare in machining workshops? Because the conditions there are more complex than in an assembly line, and design errors are more frequent.

Machining is not a linear flow. An assembly line often operates like a synchronized system, where the stoppage of one station immediately blocks the whole. In machining, machines are often more independent. Some run autonomously, others heavily depend on an operator. The stoppage of a machine does not always have an impact that is instantly visible on the overall flow. This apparent tolerance for stoppages makes the andon less instinctive.

Stoppages in machining are very varied in nature. Normal stoppages, expected, related to series change, control, adjustment, maintenance, or forced. If the andon does not make a difference, it becomes immediately noisy. And a noisy system is an ignored system.

The third reason is cultural. In many workshops, the stoppage of a machine is experienced as local management. The operator adapts, resolves, restarts. The problem is that this adaptation is often invisible: the workshop loses time, but the system does not learn it. Lean, on the contrary, seeks to make problems visible to address them sustainably, not to sanction, but to improve.

Finally, the reason is technical. Many workshops have tried solutions too simple, based on raw machine states, without context. The result is a screen that displays colors, but says nothing about the severity, the probable cause, or the action to be taken. Such an andon becomes a wallpaper industrial.

👉 Do you want an andon that triggers action, not just another screen? Connect each stop to its cause and the right person with real-time machine data. Let's talk about your workshop.

What a useful andon in machining is

A useful andon is not a system that says “it’s running” or “it’s not running.” It is a system that helps make an immediate decision. To do this, it must answer three questions as soon as a problem arises.

What is happening exactly? Is it a stop? A normal break? An end of cycle? A tool change? An operator wait? A machine alarm?

A 30-second stop does not have the same impact as a 20-minute stop on a bottleneck machine. A cycle drift on a critical series does not have the same impact as a micro-interruption on an unloaded machine.

Who needs to act? Can the operator resolve it? Is maintenance, methods, quality, or the team leader needed? And within what timeframe?

A useful Andon system is therefore more than a signal. It provides contextualized information.

The modern andon: machine status, context, and escalation

This is precisely why we now speak of the modern Andon. In machining, a modern Andon system must combine three essential dimensions.

The machine status, because the machine is the main source of events. It is important to know if it is producing, if it is stopped, in alarm, waiting, or being adjusted. Without this basis, the andon is blind.

The context, because raw status is not enough. A stopped machine is not necessarily a problem: it may be in a series change, in control, or waiting for planned material. The context distinguishes the anomaly from the normal and allows understanding of the impact on the flow. The andon then becomes a Lean tool, not just simple supervision.

The escalation, because the ultimate goal is the reaction. A detected anomaly must trigger an action, defined in advance and stable. Without escalation, the andon remains passive. With a clear escalation, it becomes a performance driver.

The green/red trap: why it doesn't work

In many implementations, Andon is reduced to a workshop overview with green and red status indicators. It looks appealing because it is simple. However, it is ineffective for three reasons.

First, the green/red does not provide context. A red machine may be in normal stop; a green machine may produce with a cycle that is significantly drifting. Next, it does not give priority. In a workshop of ten, twenty, or fifty machines, there will always be reds, and the human brain cannot process a list of reds continuously. Finally, it does not assign responsibility: who intervenes, when, according to what rule? Without an answer, the andon changes nothing.

A useful andon is not a screen. It is an organization.

Defining escalation rules: the heart of success

The most important aspect of an Andon system in a machining workshop is the definition of escalation rules. This is often the most challenging part, because it requires the workshop's actual operating procedures to be clearly defined.

An escalation rule must be simple, understandable, and applicable. It must avoid false positives: the goal is not to trigger an alert for every event, but when an event exceeds a threshold and threatens performance. A stop of a few seconds may be normal. But a stop of several minutes, on a critical machine, in full series, must trigger an intervention. Similarly, a cycle drift beyond a threshold must generate an alert, as it degrades the capacity even to generate a failure.

The rule must specify who intervenes in first. If the operator is autonomous on a type of incident, escalation should not unnecessarily engage maintenance. If the incident exceeds field competencies, escalation must be quick. Finally, escalation must be traceable: an andon is a Lean tool, it must feed the continuous improvement by identifying recurring stops, dominant causes, and main losses.

Without this feedback loop, an Andon system becomes nothing more than a permanent firefighting tool. With it, it becomes a powerful driver of production stability..

👉 Do your micro-stops cost you more than your breakdowns? Make them visible and prioritizable to act before they degrade your OEE. Request a demo of Atsora Tracking.

Reducing reaction time: the true ROI of the andon

The return on investment of an Andon system in machining should not be measured solely by OEE or machine availability. Above all, it should be measured by how much it reduces response time.

In many machining workshops, the most costly loss is not the machine stop itself. It is the time between the stop and the start of corrective action. The machine stops. No one notices. Or everyone notices, but no one knows who should respond. Or the right person is notified—but too late. Meanwhile, valuable production capacity is lost.

A modern Andon system dramatically reduces this delay. It makes machine stops immediately visible, helps determine whether they are normal or abnormal, triggers escalation when necessary, and enables the team leader to prioritize the right actions.

It is this reduction in response time that transforms performance—often much faster than a traditional Lean initiative. The workshop becomes more efficient, more predictable, and more stable.

Atsora and the andon in machining: action-oriented management

In a machining workshop, an Andon system should be built around machine data, because it is the only reliable and continuous way to detect operational events. However, machine data only creates value when it is transformed into actionable decisions.

Atsora Tracking is built around this approach: making anomalies, machine stops, cycle drifts, and other significant events visible, then enabling structured operational management through escalation and prioritization. The goal is not to add more screens. The goal is to make Lean more responsive, more practical, and more valuable for the machining workshop.

A modern Andon system is not about colors. It is a system that connects machine status to action.

To remember 

An andon is a complete system that combines detection, visibility, and response, not just a simple display. In machining, it loses its effectiveness when it is limited to a green/red screen, without context, prioritization, or escalation rules. A truly useful andon allows you to understand what is happening, assess the severity of a situation, and quickly identify who needs to intervene. Its true return on investment lies in reducing response time to stops, often faster than a traditional Lean project. 

Transform your stops into quick reactions

 

An effective andon starts with reliable machine data and action-oriented management. We help you make your stops visible, contextualized, and prioritized, to sustainably reduce your reaction time. Request a demo of Atsora Tracking and see what your workshop can gain.

FAQ – Andon in machining