Andon
An Andon is a visual alert system on the shop floor that signals a problem with a process or quality.
Andon is a lean manufacturing tool that communicates the status of a production line. It uses visual signals, most often colored lights, to alert operators, managers, and maintenance staff to an issue. The system empowers any worker to flag a problem as soon as it is detected.
The most common Andon system uses a stack of lights. Green indicates normal operation. Yellow signals that a team lead or supervisor is needed for assistance. Red indicates the line has been stopped due to a more serious problem. An operator typically triggers the alert by pulling a cord or pressing a button at their workstation.
Andon systems make problems visible to everyone in real time. This immediate notification prevents defective products from moving to the next stage of production. It also creates opportunities for immediate root cause analysis and problem-solving. By highlighting issues, Andon supports a culture of continuous improvement.
Implementation ranges from simple light towers to digital systems. Basic setups involve physical buttons and lights wired to a control box. More advanced Andon systems are integrated with a Manufacturing Execution System (MES). These systems can display alerts on large screens, send text notifications, and automatically log downtime events for later analysis.
An operator at a CNC machining cell notices excessive burrs on a finished part. She presses the yellow Andon button at her station. A team lead receives the alert and comes to the workstation to help adjust the tool path, preventing a full batch of out-of-spec parts.
What is the difference between an Andon cord and an emergency stop button?
An Andon cord signals a quality or process issue that needs attention. An emergency stop button is a safety device that immediately halts all machine movement to prevent injury.
Does an Andon alert always stop the production line?
No. A yellow alert typically calls for assistance while the line continues to run. A red alert usually signifies a line stoppage.
What do the different Andon light colors mean?
Typically, green means normal operation, yellow means help is needed or a potential issue is developing, and red means the line is stopped.
Can Andon be used in a job shop environment?
Yes. While common on assembly lines, the principle can be adapted. A job shop could use Andon lights on individual machines or work cells to signal for tooling, materials, or quality inspection.
How does Andon relate to Jidoka?
Andon is a key tool for implementing Jidoka (autonomation). Jidoka is the principle of stopping work immediately when a problem occurs, and Andon is the system used to signal that problem.
Lean Manufacturing
Lean manufacturing is a production method focused on maximizing customer value by systematically eliminating waste from processes.
Poka-Yoke
Poka-Yoke is a lean manufacturing method that uses simple mechanisms to prevent human errors from occurring in a process.
Kaizen
Kaizen is a philosophy of making continuous, small improvements in processes and products, involving all employees.
Continuous Improvement
Continuous improvement is the practice of making small, ongoing changes to manufacturing processes to increase efficiency and quality.
Total Productive Maintenance
TPMTotal Productive Maintenance (TPM) is a strategy that makes equipment maintenance a shared responsibility for all employees to improve productivity.