Ultimate Guide to Andon Systems

What is an Andon System?

A component of Lean Manufacturing, an Andon system is a communication scheme used to signal workers in manufacturing that there is a problem with a process or quality. The term Andon comes from the Japanese word meaning “lantern” and was first used in manufacturing by Toyota to describe the signal system it created for its assembly lines to improve human response time when problems arose in the manufacturing process. In an Andon system, when the signal is triggered, all production stops and the designated team member(s) tend to the issue immediately. This makes it possible to correct quality issues before they become a bigger, more expensive problem. It also makes it easier to find the root cause of the problem since mistakes aren’t covered up by other processes further down the line.

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The Lean Principle Behind Andon

Andons are based on the Lean pillar, Jidoka (aka autonomation, or “automation with a human touch”), where manufacturers employ both automation and humans in the building process. Partial automation is less expensive than full automation and can speed up tasks, while humans are supremely qualified for and efficient at certain tasks. So, Jidoka reduces labor costs and improves quality at the same time. An example of Jidoka is the situation where several machines perform a task automatically, increasing efficiency, but a person monitors the equipment making sure that any defects are found before the defect is mass produced.

Elements of Andon Systems and How They Work

Originally developed by Toyota, the Andon cord (rope) was implemented on the manufacturing line so that when pulled, the Andon light illuminated, the line stopped, and workers knew there was a problem they had to fix before the line could restart. 

Andon Stack Lights

A need to communicate different types of statuses brought with it different colors of lights. Stacked on top of each other, the color of the lit Andon light indicates what is going on with that part of the line and what should be done. Each manufacturer can establish its own meanings behind each, but here are some common states and what they mean.

  • Red: Production must stop, and a supervisor or technician is needed
  • Yellow: A problem has appeared that needs to be fixed
  • Green: Status is normal, no action is needed
  • Blue: An issue that needs addressed has been detected and needs attention soon
  • White: No problems, but line is stopped (for shift change, cycle completion, or any reason other than a problem)

Andon Button Boxes

As technology has evolved, many manufacturing facilities use button boxes instead of cords at their workstations. These boxes usually house anywhere from two to five buttons that you can assign different meanings. When a button is pressed, the corresponding light color illuminates to alert everyone on the shop floor of the change in status and what action is required based on the meanings you have predefined.

Andon Boards

Andon systems may also include more complex boards. In addition to stack lights and button boxes, these boards provide an easy-to-see view of production status across a larger area. And they sometimes will show other Key Performance Indicators such as production time and goals.

Andon in the Cloud

Cloud-based platforms are improving Andon systems today. For example, Shop Floor IQ’s online shop floor management platform allows companies to use both physical and virtual Andon stack lights to speed response time when an issue is identified. With the push of an Andon button, the nearest available quality inspector, weld inspector, management and critical machinery/assets can be automatically messaged and dispatched to a station so that downtime is minimized or eliminated. Moreover, historical analytics provide insight into the frequency of Andon states, allowing supervisors and managers to identify specific issues in the manufacturing process.

Benefits of Andon Systems

Andon systems provide a variety of benefits when they are used as intended, including:

• Improved quality: When workers are encouraged to stop mistakes, they feel trusted and take pride in the product that they helped perfect, resulting in a better quality product.

• Increased productivity and reduced downtime: Problems are identified and resolved immediately, often before the line must stop production.

• Cost and time savings: When communication is clear and concise, and people react immediately, the manufacturer saves time and money.

• Increased visibility: Knowing where on the line that issues arise, managers can identify areas of improvement in their facility.

Problems with Andon Systems

You may have heard some stories about Andon systems not working for some manufacturers. If an organization is not finding value in their Andon system, they are probably not using it correctly. Andon lights are only the first step in fixing a problem on the line. Just because the line is moving again doesn’t mean the issue is fixed. It means the symptom was treated. It’s important to identify and fix the root cause. 

One way to do this is the 5 Whys method. This Lean method involves repeatedly asking, “what were the factors that directly resulted in the effect?” until the root cause is determined. While the root cause may present itself in fewer or more questions, five whys seems to be the most common number. 

In his book, The High Velocity Edge, Steven Spear gives an easy-to-understand example of how to use the 5 Whys method to solve the problem of a car that won’t start.

  • Why? – The battery is dead. (First why)
  • Why? – The alternator is not functioning. (Second why)
  • Why? – The alternator belt has broken. (Third why)
  • Why? – The alternator belt was well beyond its useful service life and not replaced. (Fourth why)
  • Why? – The vehicle was not maintained according to the recommended service schedule. (Fifth why, a root cause)

After determining the root cause, a more permanent solution can be implemented. In the aforementioned example, regular maintenance would likely prevent the problem from recurring. Sometimes, there are several root causes, all of which should individually be solved. 

For Andon systems to be effective, the manufacturer’s culture must be such that people feel comfortable stopping the line. And instead of getting caught up in firefighting when issues arise, workers should be encouraged to work through the root cause of problems. 

While we hope you learned a lot about Andon systems here, we realize you may have more specific questions if you are considering implementing an Andon system in your facility. Using our fully integrated rules-engine, you are able to configure Shop Floor IQ to work the way your manufacturing operations work, and we’d love to show you how. Contact us for a free consultation today.

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