Andon and Visual Management on Paper Container Lines: A Shop Floor FAQ
A busy container hall in Poland had no broken machines and no idle people, yet the same small delay repeated every shift: an operator would clear a jam, walk to the office to report it, and return to find the next stop unobserved. The plant added a signal lamp and a stop timer to each main station, and the gap between a fault and a technician arriving fell within a month. Yoco Group supplies and services paper container lines, and visual management is one of the cheapest improvements a plant can make after commissioning. This FAQ answers five questions about andon and visual management on container machinery.
What does andon mean on a paper container line?
Andon is a signalling system that makes the state of the line visible without anyone having to ask. On a container line the state that matters is whether each station is running, stopped, starved or blocked, and how long it has been that way. A green lamp, an amber lamp and a red lamp carry that information to the whole hall at once, and a small display with the stop reason and a timer carries the detail to the technician who is walking over. The purpose is not decoration but the removal of the small delays that come from discovering a fault by walking to ask someone about it.
What should a visual management display show, and what should it leave out?
A display should show the few facts that change a decision and leave the rest to the process data system. For a container line that means the running state of each station, the direction of waiting when a station is starved or blocked, the duration of the current stop, and the reason for it in a small set of clearly named codes. It should also show output against plan for the shift. What it should not show is every reading on the machine, because a screen full of data is not visual management and operators learn to ignore it. A signal that is never wrong and never ignored is worth far more than a dashboard that is technically complete.
ISO 22400 defines key performance indicators for manufacturing operations management and stresses that indicators must be defined precisely and linked to the process they describe. A visual signal is useful only when the state it shows is the same state the plant measures.
How is the andon logic usually built on a container line?
The logic is usually built into the machine control system, because the controller already knows whether a drive is enabled and whether a sensor is made, so the indication can be derived from existing signals rather than from a separate set of sensors. The same controller can push the stop timestamp to a small display and to the plant network, which makes the signal and the stoppage log the same data. Where a line is older and the controller has no spare outputs, a separate sensing layer can be added, but the cost rises and the data quality usually falls. The design choice is therefore a question about the control system as much as about the lamps.
How do you keep operators from ignoring the signals?
The single rule is that a lamp must mean what it says. If an amber lamp can mean either a genuine slow cycle or a sensor that has drifted, operators will learn to distrust it and the system will quietly stop working. A plant should define the meaning of each colour in writing, test it against the machine control before go-live, and treat a false signal as a fault to be corrected rather than an accepted nuisance. The second rule is that every signal must lead to an action, because a lamp that shows a condition nobody is expected to fix teaches people that signals do not matter. Each colour should map to a named response and an escalation time.
How does visual management connect to maintenance and to the shift routine?
Visual management pays best when it feeds the routines the plant already holds. The line summary at the end of a shift should come from the same signal data as the display, so the morning meeting discusses what the operators saw rather than a number reconstructed overnight. On the maintenance side, a signal system that records the reason and the duration of every stop gives the planner a same-day view of which stations are interrupting output, instead of waiting for a monthly report. That immediacy is the whole point: information that arrives while it can still change the shift is worth more than a perfect report that arrives after the month has closed.
Prepared by 燕七.