Dear Gemba Coach,
I understand the problems, and I’ve seen only a couple of real andons developed outside of Toyota so there is a very real difficulty. As with so many lean tools, the issue about andon is not the andon itself: pushing a button or pulling a chord to light up a signal board to call for help is no big technical challenge. The issue is with the human underpinning of the andon: what is the benefit? Who does what how, and to what purpose? And here we find that andon lies at the heart of TPS thinking, precisely where it differs so starkly from mainstream management thinking.
First off, let’s clear a frequent misconception: andon is not an alarm button. We’re all familiar with alarm calls: call 911, pull the emergency lever on the train, push the big red emergency stop button on a machine. We understand instinctively that when something goes very wrong, we should sound the alarm and get a reaction. This, however, shouldn’t happen frequently, but only when there is a “real emergency.” Many people who try to set up andons believe these should be pulled or pushed when there is a “real” problem, as an emergency button – which means infrequently.
When you stand on a Toyota line, the andon gets pulled quite often – you’re always hearing an andon alarm somewhere on the line, and it’s not rare to catch an andon pull if you’re walking leisurely through the line. On one segment, andon is likely to be pulled at least once within the hour. This is not an emergency call, this is normal, routine work. Have operators so many problems? Is Toyota quality really so problematic?
The andon pulls I’ve seen firsthand where not about quality issues but operators signaling they were late on their work cycle. The team leader showed up immediately to help (which meant the team leader knew how to help) by taking up a minute part of the job and getting the operator back in his or her rhythm. Mostly, the issue was a difficulty in the flow of work, in the standardized work, and only once have I seen a real doubt about the quality of a supplied part.
The First Andon
To fully grasp andon, we need to go check our understanding of kaizen, standardized work, and team leaders. In his account of the early days of TPS at Toyota, Takehiko Harada (Management Lessons from Taiichi Ohno) recalls how the first andon was put on the engine machining line in Toyota’s Honsha plant, and progressively generalized from there. When you felt that you were going to be late, you pushed the call button, which lit up the andon yellow light – red is for safety emergencies, yellow is a request to come over, white is a signal that something needs to be changed on the machine and the question is how to do this better.
To explain how the andon came about, Harada goes back to how team leaders first appeared. In his account, Taiichi Ohno handpicked operators with whom he had had good kaizen experiences and staffed them on segments of the line to support further kaizen. Progressively this role evolved into team leaders. Their job was to (1) maintain standards, (2) lead kaizen, (3) through “5 whys” analysis of the difficulties encountered in maintaining standards, or, to be more specific, standardized work: the sequence of feet movement, hand movements and eye movements that made work flow the most naturally and efficiently within one cycle.
As Toyota engineers worked out the overall flow of work, dividing lines in segments, and automated machining lines in segments, they added andons to show when a part didn’t go through a section, so that the team leader would know where to intervene. When the andon is not flashing, the team leaders’ job is to find the root cause to the last andon flash and figure out how to keep this from happening again. To sum up, the andon calls the team leader’s attention to an abnormal situation where he or she must:
- Get the situation back to normal right away if they can.
- Let the line stop if they consider the line can’t operate this way, and then help the supervisor to get the line moving again as quickly as possible.
- Think deeply about the causes of andon pulls and kaizen to improve standards and smooth further the flow of work.
Andon therefore makes sense in a situation where (1) line sections or segments are clear, with clear, stable, teams working there; (2) the pull of work is clear so that the teams can see whether they’re ahead or late, (3) a team leader is assigned to the team and responsible to make things better through maintaining standards and looking for kaizen opportunities and (4) the focus of distinguishing normal from abnormal is within every operator cycle.
How to Start an Andon Experiment
Lean tools often are about brining management functions to the shop floor to develop local autonomy. Andon brings to the shop floor the responsibility for standard work: smooth, safe, hassle free flow of work. To do so, we need to look at the stumbling blocks to doing a good job that operators come across, in terms of having enough trained people to do the job (manpower), having the right materials to do the job (materials), available and easy-to-use equipment (machine) and the right understanding of standard work (method).
Before you experiment with andon, you can start by going back to your gemba and checking how three very simple lean tools are used at shift level, then at hourly level:
- Hourly production analysis board: Can all teams see clearly what is expected, whether they’re ahead or late and have a place to express their opinion on what is holding them back?
- Red bins: Have all operators a clearly identified place to put doubtful parts, call their leader, check whether the part is OK or not-OK, and trigger an investigation and problem solving when the part is defective?
- Team leaders: Are all operators organized in five-person teams with a team leader to show how standard work should be performed and support kaizen initiatives in the team?
Without such basic elements in place to make sure management is at least concerned about what happens to teams at the shift level, it’s going to be very hard to narrow down problem solving at the hourly level and then, with andon, at the level of every work cycle.
Where to start is definitely with local management’s attitude to kaizen and standard work, and it’s probably smarter to start with simpler (bot not necessarily easier) tools such as hourly boards and red bins to work on management’s attitude to operator difficulties within the shift and then within the hour before reaching doing so continuously through andon.
Andon is not so much a system to increase management reactivity, but one to support operator training (the team leader checks the standards and teaches the standard way to do the job) and kaizen by orienting team leaders toward what needs to be improved right now. Both can be developed without the full andon mechanism at first and then andon will come naturally as people themselves narrow their time perception of what is normal and abnormal. Success with andon rests on your commitment to kaizen and standard work.