The word Andon is Japanese, and its origins comes from the use of traditional lighting equipment. It is now a commonly used term in lean manufacturing where it is used as a signal to highlight an anomaly using a visual system of communication that is often relayed with a lit signboard or stacked lights. It may also be able to be activated automatically by the production equipment. It means to stop production may also be included in the system so issues can be corrected immediately. Some advanced alert systems incorporate text, audio alarms, and other forms of visual displays.

To understand Andon, you must understand how it supports the Jidoka quality control method. It originates with the Toyota System Corporation where the company first implemented the process of stopping a system when a defect was suspected. The concept behind Jidoka is that once the system is stopped, you get an immediate opportunity for improvement. Since there is more opportunity to find the root-cause of problems, there is a lesser chance of letting the defect continue further down the line and remaining unresolved.

Jidoka also referred to as “automation,” is used in lean manufacturing to highlight a problem as it occurs to immediately introduce counter measures that will help prevent the problem from reoccurring. Andon is a principal and a typical tool that is applied to the Jidoka principal. It is activated using a pull cord or button so that:

1. The team can gather together
2. Apply the Plan-Do-Check-Act (PDCA) Cycle
3. Apply root-cause analysis
4. Quickly apply a solution

The concept of giving permission to make a line stop to a non-management worker, particularly someone working on the production line, was pioneered by W. Edwards Deming. The benefits of using an Andon are:

Better design of products provide improved service
An increased level of uniform product quality
A higher level of product testing and the workplace and independent research centers
Greater sales through global markets

These systems are very valuable in manufacturing, particularly when used in conjunction with plant-wide supervisory control and data acquisition (SCADA) systems that have the ability to send Andon-related data where it is needed the most such as control rooms or maintenance departments. A fully functioning Andon-powered system eliminates reliance on clipboards, whiteboards, and word-of-mouth for instant and up-to-date status information on plant cycles.

Common reasons for workers to manually activate the Andon alert is:

Part shortage
Tool malfunction
Defect created or found
Existence of a safety problem

Once the alert is signaled, work is stopped until a solution has been found. Alerts are then logged into a database by management as part of a continuous improvement program.

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Types of Andon

There are two types of andon: manual and automatic. A manual type is activated manually by the employee or operator on the assembly line by either pulling a cord or pressing a static button. Automatic andons are activated automatically on the conveyor when specific criteria that are assigned on the assembly line is lacking or not met. These are in the form of light signals in the manufacturing process to enable the operator to signal the status based on the indicator light color. They also help organizations to not rely on whiteboards, clipboards, word-of-mouth, email, or the Internet as a communication tool.

Today, our Andon boards and visual displays are more technologically advanced to include the introduction of status board mobile apps which is helping to redefine the role of status boards. However, they all serve the same purpose as a highly effective tool to enable the operation to run smoothly without any bottlenecks by communicating efficiency and real-time status of the plant floor.