Key takeaways
  • Visual management makes the difference between normal and abnormal visible without anyone having to ask or calculate.
  • An andon signal is worthless unless a defined response happens within a defined time. The response is the system; the light is the interface.
  • Boards become wallpaper when they show data nobody acts on. Show the gap against a target, not the raw number.
What makes an andon real
A defined responder and a defined response time

A cord that stops the line is not the mechanism. The mechanism is that pulling it summons a specific person within a specific number of seconds, and that this is honoured every time, including when the plant is behind schedule.

The principle

Good visual management means someone unfamiliar with the area can tell in a few seconds whether things are normal. That is a higher bar than displaying information, and it rules out most dashboards, which require reading and interpretation.

What makes a signal work

  • It shows a state, not a number: normal, attention, stopped.
  • It is visible from where the work happens, not from an office.
  • It has a named responder and a target response time.
  • The response is honoured even when inconvenient, or the signal stops being used.
  • Every activation is recorded, because the pattern is more valuable than any single event.

Why boards become wallpaper

  • They show raw output rather than performance against a plan, so nobody can tell if it is good.
  • They are updated weekly, which is too slow to act on.
  • Nothing changes as a result, so reading them stops being worthwhile.
  • They are placed where managers walk rather than where the work is.

A board worth keeping

Plan versus actual for today, updated at least hourly by the team, with a space to write the reason for any gap. The reasons column is the valuable part: it becomes a Pareto of your real losses at no additional cost, and it is written by the people who know.

Recording activations

The pattern of andon calls is a free improvement backlog: which station, which shift, which cause, how long until response. Capturing each activation as a short record at the moment it happens turns a signalling system into a data source, and that is usually where the larger long-term value sits.