Andon
Is Andon just a warning light?
No. It is a visual management and escalation system that communicates an abnormality and drives immediate action, often including line stop, root-cause review, and corrective response.
Can Andon be used for materials management instead of machine faults?
Yes. Sources explicitly note use for materials shortages, inventory requests, forklift calls, and kit management in internal logistics.
Does Andon always stop the line?
Not always. Some systems are designed to stop production for defects or severe shortages, while others simply signal and escalate without stopping, depending on the process design and severity rules.
Andon is a real-time visual management and escalation mechanism used in manufacturing and lean supply chains to signal abnormalities such as machine downtime, quality defects, or materials shortages. It typically uses overhead light boards, stack lights, buttons, or pull cords to alert supervisors and support teams, enabling immediate response, line protection, and continuous improvement.
An operator pulls the Andon cord when a bin is empty or a kit misses a part, lighting the zone on the overhead board and sending a digital alert to a material handler. In lean material flow, the alert is tied to replenishment rules so a forklift call dispatches immediately rather than waiting for a scheduled route. Supervisors see shortage patterns, receiving bottlenecks, and repeated line-side stockouts. The system separates normal operation from exception states, helping identify JIT failures before downstream work is starved. In supply-chain control rooms, Andon provides visibility across receiving, kitting, and assembly, supporting workload balancing and throughput protection. Connecting the visual signal to WMS or MRP prevents hidden downtime and supports root-cause review. The result is shorter time-to-replenish and fewer unplanned stops.
Alert overload / false alarms: When every minor issue triggers Andon, operators and supervisors become desensitized, response times stretch, and the system loses credibility because thresholds are poorly defined or sensors are oversensitive.
No ownership after escalation: An Andon light without a designated responder, spare-parts path, or material-handler assignment leaves visible alarms but no recovery action, so the line stays blocked while teams wait for clarification.
Poor inventory integration: When Andon is not linked to WMS or MRP replenishment rules, shortages are only noticed after parts are depleted, causing kit misses, WIP starvation, and downstream stoppages despite the alert mechanism.