The Andon systems used in today's factories look nothing like their origins. What started as simple paper lanterns in Japanese workshops has evolved into wireless digital networks with real-time dashboards and automatic escalation.
Understanding this history explains why Andon systems exist and what problems they were designed to solve—problems that remain relevant more than a century after the concept first emerged.
Origins: The Japanese Lantern
The word "Andon" (行灯) is Japanese for a type of paper-covered lantern traditionally used for lighting. These lanterns were common in Japan for centuries, providing portable illumination in homes and businesses.
The connection to manufacturing came from the lantern's most basic function: making something visible. Before electricity was widespread, a lit lantern was how you signaled that something needed attention—a shop was open, a room was occupied, or help was needed.
This simple idea—using visual signals to communicate status—became the foundation for industrial Andon systems.
Sakichi Toyoda and the Automatic Loom (1900s-1920s)
The story of modern Andon begins with Sakichi Toyoda, founder of what would eventually become the Toyota Motor Corporation.
In the early 1900s, Toyoda was working on textile looms. The problem with looms at the time was simple but costly: if a thread broke, the machine kept running, producing defective fabric until an operator noticed. By then, significant material and time were wasted.
Toyoda's innovation was an automatic loom that could detect when a thread broke and stop itself immediately. The machine would signal for attention, and only then would an operator intervene.
This principle—detect the abnormality, stop, and signal—would later be formalized as "Jidoka," one of the two pillars of the Toyota Production System.
Toyota Production System and Jidoka (1950s-1970s)
After World War II, Toyota faced the challenge of competing with American automakers who had massive scale advantages. Taiichi Ohno, working under Toyota's leadership, developed what became known as the Toyota Production System (TPS).
TPS rested on two main pillars:
- Just-in-Time — producing only what's needed, when it's needed
- Jidoka — "automation with a human touch"
The most famous tool was the "Andon cord." A rope or cord ran along the assembly line, and any worker who spotted a defect or couldn't complete their task could pull it. Pulling the cord triggered:
- A visual signal (lights on an overhead board)
- An audible alert
- Help from team leaders or support staff
Visual boards—also called Andon boards—displayed the status of each station on the line. Green meant normal operation. Yellow meant a worker needed help. Red meant the line had stopped. Supervisors could see at a glance where attention was needed.
Western Adoption (1970s-1990s)
By the 1970s, Japanese manufacturing—particularly automotive—was outperforming Western competitors in quality and efficiency. Researchers and consultants began studying Toyota's methods.
The term "lean manufacturing" emerged as the Western label for these practices, popularized by the book The Machine That Changed the World in 1990.
As Western factories adopted lean principles, they also adopted visual management tools. Stack lights—those tri-colored towers (red, yellow, green) mounted on machines—became standard equipment on factory floors worldwide.
Stack lights worked, but they had limitations:
- Passive notification — someone had to be looking at the light to notice
- No data capture — there was no record of how long a condition lasted
- No escalation — if no one saw the light, nothing happened
- Limited range — only visible in the immediate area
The Wired Era (1990s-2010s)
The next evolution addressed the limitations of passive visual signals. Electronic paging systems allowed alerts to be sent directly to responders, wherever they were in the facility.
Instead of cord-pulls, operators pressed buttons to signal for help. The signal traveled through wired infrastructure to a central unit, which dispatched alerts to pagers carried by maintenance techs, quality inspectors, or supervisors.
This was a significant improvement:
- Active notification — responders received alerts directly
- Broader reach — alerts could find responders anywhere in range
- Some tracking — systems could log when calls were made
These wired systems also required infrastructure. Running cables through a factory meant installation costs and inflexibility. Moving a workstation meant rewiring.
Modern Andon: Wireless and Digital (2010s-Present)
The current generation of Andon systems reflects advances in wireless technology, computing, and software.
Wireless communication removed the installation barriers. Call buttons could be placed anywhere and moved as needed. Responders could wear watch pagers that worked across large facilities without being tethered to fixed locations.
Software dashboards replaced the simple visual boards of the Toyota era. Digital displays could show real-time status on any screen—dedicated monitors on the floor, TVs in break rooms, or laptops in supervisor offices.
One manufacturer, evaluating their options, asked whether they'd "need to get lights out there." The answer: "No, you don't need to get lights. This is a system where you'll be able to view it on your PC."
Escalation logic addressed the problem of missed calls. If a call went unanswered for a set time, the system could automatically notify a backup responder or supervisor—something impossible with stack lights or basic paging.
Data and reporting became the major differentiator. Modern systems track not just that a call occurred, but how long the operator waited, how long the repair took, who responded, and what type of issue it was. This data feeds continuous improvement efforts in ways that previous generations couldn't support.
Andon in Industry 4.0
The evolution continues. Current trends include:
Integration with other systems. Andon data can flow into Manufacturing Execution Systems (MES), Enterprise Resource Planning (ERP) systems, or business intelligence platforms. API connectivity allows custom integrations with whatever systems a plant already uses.
Mobile access. Supervisors and managers can view status and reports from smartphones and tablets, not just fixed workstations.
Predictive applications. With enough historical data, patterns emerge. Some facilities use Andon data to predict which stations are likely to have issues, enabling proactive intervention before problems occur.
Machine-triggered alerts. Beyond manual button presses, PLCs and sensors can automatically generate Andon calls when machines enter fault states or when process parameters drift out of specification.
What Stays the Same
Despite a century of evolution, the core principle remains unchanged:
Make problems visible immediately. Whether through a paper lantern, a cord-pull, a stack light, or a wireless pager, the goal is the same: don't let problems hide.
Empower frontline workers. Sakichi Toyoda's insight—that the person closest to the work is best positioned to detect abnormalities—remains valid. Modern Andon systems still put the alert trigger in the hands of operators.
Respond quickly. The value isn't in the signal itself but in the response it enables. A sophisticated digital dashboard provides no value if calls go unanswered.
Continuous improvement. The Toyota Production System wasn't just about solving today's problems; it was about building the capability to solve tomorrow's problems faster. Modern Andon data supports this ongoing improvement cycle.
The Evolution Continues
Manufacturing plants today describe their older systems as "failing" or "unsupported" after seven or eight years—driving another upgrade cycle. Each generation of technology solves limitations of the previous generation while creating new possibilities.
Current systems are defined by data and connectivity. The next generation will likely be defined by intelligence—systems that not only capture information but help interpret it, suggest actions, and predict outcomes.
What won't change is the underlying problem: production issues happen, and someone needs to know about them fast. The history of Andon is the history of solving that problem, one innovation at a time.
Frequently Asked Questions
Why is it called "Andon"?
"Andon" is the Japanese word for a paper-covered lantern. The term was adopted in manufacturing because the earliest industrial applications used lights to signal status—a visual cue visible to anyone watching, much like a lantern.
Do modern systems still use cord-pulls?
Some do, particularly in facilities with strong Toyota Production System traditions. But most modern implementations use buttons or automated triggers instead. The principle is the same; only the mechanism has changed.
What did factories use before Andon?
Before Andon, factories relied on supervisors walking the floor, workers shouting or waving, intercoms, and radios. These methods still exist but have significant limitations compared to systematic Andon approaches.
Is Andon still relevant today?
Yes. The problems Andon solves—production delays, quality issues, communication gaps—exist in every manufacturing environment. The technology has evolved, but the need for fast, visible, accountable problem signaling remains.
Learn More
Understanding Andon's history provides context for evaluating modern solutions. The technology has changed dramatically, but the core value proposition—making problems visible so they can be solved quickly—remains the same.
Related reading: