Key takeaways
Short answer: Andon and kanban are both lean signalling tools, and they are often confused, but they solve opposite problems. Andon is an exception signal — it shouts there is a problem here, come now, stopping the line if needed so a defect is not built into the next hundred units. Kanban is a flow signal — it quietly says we need the next batch, pulling work only when demand exists so you do not overproduce. One handles trouble; the other handles pace. For the wider system, see OEE for manufacturing.
Andon is the line's alarm system, and its philosophy is radical: empower anyone — often any operator — to flag or even stop production the moment something is wrong. A pulled cord or pressed button lights a board, calls a team leader, and makes the problem visible immediately, before a defect is repeated down the line. The point is not the light; it is the response culture behind it — that a stop for a real problem is treated as the right call, not a failure. Andon trades a small, controlled stoppage now for a large, expensive batch of defects avoided later.
Kanban is a flow-control signal, and its philosophy is restraint: produce only what the next step actually needs, when it needs it. A card, bin, or electronic trigger authorises replenishment as stock is consumed, so work is pulled by real demand rather than pushed by a schedule that may be wrong. The result is less inventory sitting between steps, less overproduction, and a visible cap on work in progress. Where andon is loud and exceptional, kanban is quiet and continuous — a steady heartbeat that paces the line to genuine consumption.
The cleanest way to keep them straight: kanban is a pull signal, andon is an exception signal. Kanban fires constantly as part of normal operation, regulating how much and when. Andon fires only when something deviates — a defect, a shortage, a safety issue — and demands human attention. Kanban is designed so the line runs smoothly without anyone shouting; andon exists precisely for the moments when someone must. Confusing the two leads to real mistakes: using andon to manage routine flow creates alarm fatigue, and using kanban to handle a quality emergency means the defect propagates while the card waits its turn.
On an assembly line, kanban governs the steady state: as the packing station consumes finished units, kanban signals upstream to build the next batch — no more, no less — so inventory between stations stays low and nobody overproduces. Then an operator spots a misaligned weld. She pulls the andon. The line halts, a team leader arrives in under a minute, the root cause is corrected, and production resumes — and crucially, the bad weld was not built into the next 200 units. Kanban kept the line lean all shift; andon stopped one defect from becoming a recall. Same line, two signals, two jobs.
Reach for kanban when the problem is flow: too much inventory between steps, overproduction, unclear replenishment, or work pushed regardless of demand. Reach for andon when the problem is response: defects slipping downstream, problems staying invisible until inspection, or operators lacking a fast, sanctioned way to raise the alarm. Most lean implementations need both, because a line can flow beautifully and still build defects, or catch every defect and still drown in inventory. They are layers of the same system, not competing options.
The two signals protect different parts of OEE. Andon defends the quality factor — and often availability — by catching defects early and surfacing the stoppages that would otherwise hide as losses. Kanban defends flow: by capping work in progress and matching output to demand it reduces the overproduction and waiting waste that erode effective performance. Neither is an OEE metric itself, but both move the numbers — andon by protecting good output, kanban by protecting smooth flow.
Fabrico makes the problems these signals respond to measurable. When an andon stop happens, it is captured as a downtime event with a reason code and folded into OEE, so you can see which problems pull the cord most often and fix the recurring ones. When flow stutters, the performance and micro-stop data show where. Signals tell the floor what to do now; Fabrico tells the team what keeps happening and what it costs. Book a demo to connect your lean signals to live OEE.
Andon is an exception signal that flags or stops the line when there is a problem, pulling immediate attention. Kanban is a flow signal that authorises the next work or replenishment based on real demand. Andon handles trouble; kanban handles pace.
No. They solve opposite problems — andon is for real-time problem response, kanban is for controlling flow and inventory. Most lean lines use both together rather than choosing one.
The light is only the visible part. Andon is really a response system: anyone can raise it, and the organisation commits to reacting fast and fixing the root cause. Without that response culture, the light is just decoration.
Kanban limits overproduction and excess inventory by pulling work only when the downstream step needs it. It caps work in progress and paces production to actual consumption rather than a push schedule.
Andon protects the quality and availability factors by catching defects and stoppages early; kanban protects flow by reducing overproduction and waiting waste. Both move OEE without being OEE metrics themselves.
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