Andon Visual Display: From Signal Lantern to Live Plant Data
Toyota installed andon boards in 1966, and most plants still run the same premise: a light comes on and someone is supposed to notice. Here is what a modern Andon visual display should show, where the data comes from, and who else needs to know.
Toyota installed the first andon boards on its production lines at the Kamigo Plant in 1966. Sixty years later, most plant floors still run on the same basic premise: a light comes on, and someone is supposed to notice.
The hardware has improved enormously. The harder question, what the board actually knows and who finds out, has not moved nearly as far.
An Andon Visual Display earns its place when it stops being a lamp and starts being a live view of plant state. That shift depends less on the screen than on what feeds it.
What an Andon Visual Display Is, and Where It Came From
“Andon” is the Japanese word for a paper lantern. In the Toyota Production System, Toyota describes the andon as the problem display board that lights up to notify workers when equipment stops. The Lean Enterprise Institute defines the andon board as a visual control: a line-stop indicator positioned where supervisors can see it.
The concept lives inside jidoka, one of the two pillars of the Toyota Production System alongside just-in-time. Jidoka traces back to Sakichi Toyoda’s early loom, which stopped automatically when a thread broke rather than continuing to weave defective cloth.
The light was never the point. The point was that an abnormality becomes visible the moment it happens, and that visibility triggers a response.
That original intent is the standard worth holding a modern Andon Visual Display to.
A Light Tells You Something Is Wrong. It Does Not Tell You What.
Most facilities already produce the data an Andon board needs. SCADA and MES platforms generate detailed alarm and event records. Historians store them. Operators see them on HMI screens in the control room.
The gap sits between that data and the display on the floor. Many Andon boards are wired to a small set of discrete outputs, which means they can show colour and little else.
A red light tells a technician to start looking. A board fed by the actual alarm and event stream tells that technician which asset, which fault, which priority, and how long the condition has been active.
That difference is the whole argument for treating Andon as part of your alarm architecture rather than as signage.
What a Modern Andon Visual Display Should Show
Once the board is connected to real alarm and event ingestion, the content changes. Useful displays typically carry four layers:
- Live alarm state, with asset, location, priority, and elapsed time
- Event context, so the floor sees what preceded the current condition
- Production counts against target, by line, cell, or shift
- OEE contributors, particularly availability loss
That last layer connects the board directly to a metric leadership already tracks. Vorne, which maintains the reference definition of OEE, puts world-class OEE at 85% or above, a benchmark originally defined by Seiichi Nakajima in his 1984 work on Total Productive Maintenance. Vorne reports that most manufacturers score closer to 60%, and that it encounters more plants below 45% than above 85%.
Availability loss is the OEE component driven by unplanned stops. It is also the component that responds fastest when the floor finds out sooner.
A Board That Shows Everything Shows Nothing
Alarm management standards have already worked through the discipline that visual displays need. ANSI/ISA-18.2, the standard for management of alarm systems in the process industries, recommends using no more than three or four alarm priorities, and configuring no more than 5% of alarms as high priority.
Apply that logic to a display. If every condition renders in red, the board has taught the floor to ignore red.
Prioritization and queueing are what separate an Andon Visual Display from a scrolling message board. The display should decide what deserves the screen, in what order, and for how long, based on rules your team sets rather than on whatever arrived last.
The MTTR Math That Never Makes It Onto the Board
Mean time to repair is not mostly repair. Douglas Machine, an OEM in packaging automation, estimates that hands-on repair work accounts for only 30% to 40% of total MTTR, while the remaining 60% to 70% is organizational delay: detection, response, diagnosis, and verification.
Read that figure alongside a traditional Andon setup and the opportunity becomes obvious. A display that shortens detection and speeds diagnosis is working on the largest share of MTTR, not the smallest.
No amount of faster wrench time compensates for twenty minutes of nobody knowing.
Every Screen You Already Own
Display hardware on a plant floor is rarely uniform. Facilities accumulate LED marquees from several vendors across decades, plus standard LCD monitors, projectors, and newer digital signage.
SeQent’s Andon Visual Display capability is built for exactly that reality. Marquee Manager drives industrial digital signage across modern and legacy displays from multiple vendors, and VideoSERVER extends the line to full template control for fixed and mobile screens, connecting standard monitors, projectors, and digital signage over TCP/IP.
On the input side, the platform reads from the systems you already run: OPC Classic and OPC UA, ODBC, AVEVA InTouch, System Platform, and PI, Velotic (formerly GE Vernova) CIMPLICITY and iFIX, Rockwell FactoryTalk View SE, and PTC ThingWorx. SeQent has been a Rockwell Automation Technology Partner for 15 years.
The practical result is that upgrading what your Andon boards show does not require replacing the boards.
A Board Only Helps the People Looking at It
A fixed display has one structural limitation: it reaches whoever is in front of it. At 2 a.m., in an adjacent building, or inside a zone nobody is walking, the board is a record rather than an alert.
This is where an Andon Visual Display works best as one output among several. FirstPAGE Alarm Manager (FPAM) manages the full alarm lifecycle and routes the same event to Motorola two-way radios, smartphones, PA systems, and pagers, escalating automatically through a defined hierarchy until someone acknowledges. The board spreads awareness across the floor. FPAM makes sure the specific person responsible finds out.
Workforce trends make that pairing more valuable, not less. Deloitte and The Manufacturing Institute estimate that US manufacturing may need as many as 3.8 million new employees between 2024 and 2033, with up to 1.9 million of those roles potentially going unfilled. In Canada, Canadian Manufacturers & Exporters reported that more than 80% of manufacturers faced labour and skills shortages in 2021 and 2022, with roughly 700,000 skilled workers expected to retire nationally by 2028.
Fewer experienced people on the floor means fewer people positioned to interpret a light and know what it means.
Where to Start
Auditing an existing Andon deployment usually comes down to four questions:
- What data source actually drives the board today, and how much of your alarm and event detail never reaches it?
- How many priority levels does the display distinguish, and does the floor still react to the top one?
- Which zones, shifts, and buildings have no line of sight to a display?
- When a condition appears on the board and nobody responds, what happens next?
Answer those honestly and the gap between a lamp and an Andon Visual Display becomes measurable.
Toyota’s andon boards in 1966 did something specific: they made a problem impossible to miss and made a response mandatory. That standard has not changed. What has changed is how much your control systems already know, and how little of it most boards are allowed to show.
See how SeQent’s Andon Visual Display connects your existing alarm and event data to every screen on your floor, or get in touch and we will map what a faster path from alarm to action looks like in your facility.
Sources
- Toyota Motor Corporation, 75 Years of Toyota, “Andon” (andon installed at the Kamigo Plant, 1966). https://www.toyota-global.com/company/history_of_toyota/75years/text/entering_the_automotive_business/chapter1/section4/item4.html
- Toyota Motor Corporation, “Toyota Production System,” Vision and Philosophy (jidoka and just-in-time pillars; andon board lights up when equipment stops). https://global.toyota/en/company/vision-and-philosophy/production-system/
- Lean Enterprise Institute, “Andon,” Lean Lexicon (andon board as visual control and line-stop indicator). https://www.lean.org/lexicon-terms/andon/
- Lean Enterprise Institute, “Jidoka,” Lean Lexicon (jidoka as a TPS pillar; Sakichi Toyoda’s loom). https://www.lean.org/lexicon-terms/jidoka/
- Vorne Industries, “World Class OEE,” OEE.com (85% world-class benchmark, originally defined by Seiichi Nakajima, Introduction to TPM, 1984; typical scores closer to 60%). https://www.oee.com/world-class-oee/
- ANSI/ISA-18.2, Management of Alarm Systems for the Process Industries, as summarized in Exida, “Alarm Management and ISA-18: A Journey, Not a Destination” (three to four priorities; no more than 5% high priority). https://www.exida.com/articles/ALARM-MANAGEMENT-AND-ISA-18-A-JOURNEY-NOT-A-DESTINATION.pdf
- Douglas Machine Inc., “What Is Mean Time to Repair (MTTR) and What Drives It Up or Down?” (30% to 40% hands-on repair; 60% to 70% organizational delay). https://www.douglas-machine.com/what-is-mean-time-to-repair-mttr-and-what-drives-it-up-or-down/
- The Manufacturing Institute and Deloitte, “Manufacturers Need as Many as 3.8 Million New Employees by 2033” (2024). https://www.themanufacturinginstitute.org/manufacturers-need-as-many-as-3-8-million-new-employees-by-2033/
- Canadian Manufacturers & Exporters, “Manufacturing Survey: Labour Shortages and Supply Chain Disruptions Constrain Recovery” (2022). https://cme-mec.ca/blog/manufacturing-survey-labour-shortages-and-supply-chain-disruptions-constrain-recovery/
