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Andon top Andon? (the Toyota Way)

Andon? (the Toyota Way)

In our previous article Andon? (the simple way) we have learned that Andon is just a signal used to call for help when an abnormal condition (error) has been detected! If you run out of fuel, your car calls for help!

How is Toyota using Andon in their production line?
Usually Andon LIGHTS are used on the Andon BOARD to signal there is an error somewhere in the production line. The Andon Board should not be more than 10 feet away and has to be installed in a place where it can be easily seen from every operator in that area! As we have seen, Andon lights work just the same as a traffic light with 3 colors.

Green = Normal condition
Yellow = Attention!
Red = Stop!

So when everything is going smooth, we have a normal condition and the lights on the Andon board are green. If an operator detects a problem, he pulls the Andon line (or pushes a button) to call for Help. The light on the Andon board will turn to Yellow now, telling the Hancho (Team Leader) or Supervisor that Station “X” has a problem. He rushes in, the operator tells him what the problem is and he tries to solve the problem in a certain period of time. There is only a specific amount of time where the problem can be solved, depending on Takt Time!

What is Takt Time?
“Takt Time is the required pace of production to meet customer demand. If yesterday Customers have ordered 100 Camrys, so we have the need to build up 100 of them today. If Customers order 120 Camrys, there will be a change to Takt Time, as more cars have to been produced. The Takt Time is often shown on the Andon Board”

It is very important to come up with a detailed plan when an Andon is installed. Why that?
The operator pulls the line if he detects an error, a defect, or maybe even when he can’t find the tool he needs right now. The operator must be trained to tell the Hancho exactly and in very few words what the problem is (as time is running out!). During such a “Help Call” the Toyota Production Line has NOT stopped! Here the “”Fixed Position Stop System” comes in. Sound’s a bit complicated, but I will try to explain it the easy way!

We have to produce 100 Camrys today, and if we have 10 Andon “Help Calls” during the shift, each one 5 minutes, we would get a huge problem! 5 x 10 Minutes would be nearly an hour of wasted time! And we don’t want to waste the precious time! Waiting Time is a big problem in production, and Lean tries to avoid it wherever possible. Think about how many times a day you have to wait for something, for someone, for a phonecall, the computer…. Sum up this time and you will see that most of the time you are doing NOTHING but WAIT! In Production this problem is even bigger, because we can only make money with our final product. We have to meet customers demand! There are 100 customers out there that want their Camry! NOW!

Let’s go back to our Fixed Position Stop System and you will see how Toyota tries to avoid Waiting Time during Andon! The production line has not stopped, the cars are moving! They will continue moving until they reach a certain position: the fixed position! If the problem cannot be solved until the car reaches the fixed position, the whole production line will stop! And we have a problem! Waiting Time!

In the beginning there was the “Pull and Stop” Andon. If a worker pulled the line, the whole Production Line stopped. So Toyota developed the “Fixed Position Stop System”.

fixed position stop system EN Andon? (the Toyota Way)

In the picture above the red block in the third row is the amount of time we have to solve the problem!


Andon can be used efficiently only when there is a defined plan of “How To do Andon”:

Worker: Pull the line – call for Help!
Hancho: Rushes in! Doesn’t even need to ask “Hi Joe, what’s the problem?” because the..
Worker: tells him exactly what the problem is (can’t find my torque wrench, this piece is defective, don’t feel well need a substitute…)
Hancho: knows exactly where to get a torque wrench, where to get a replacement part or whom to call for replacing the worker. Time is short, problems need to be solved NOW. The Hancho has to be be very experienced, know all processes, be a Team Leader and last but not least he must have the “Gemba Sight”! He needs to analyze the root cause in a very short time! It is like a Gemba Walk in seconds!

If he is nor able to solve the problem and the line reaches the fixed position, the line stops. This is not acceptable! The root cause of the problem has to analyzed very carefully, in order to never get the same problem again. Everything must be done to avoid it in the future. So the main job of the Hancho on the Production Line is not to sit somewhere and wait for Andon lights to change to yellow, but to make shure no problem occurs twice!

So what are the big advantages of Andon?

  • If we got a problem, we can react in nearly “Zero” Time! Imagine the worker to leave his workplace searching for his hancho (THAT would be a problem!)
  • The Hancho is not only Supervisor, as the workers supervise for themselves, but he has time to solve problems
  • The Production Process can be controlled directly
  • The Worker can call for help just by a short movement with his hand
  • The Problem can be analyzed and solved in “Gemba”, the place where the problem occurred

Very interesting is that a Worker can also call for help if he is overburdened (MURI) or not feeling well. Another important Aspect of Andon is SAFETY! If a worker detects an abnormality, he pullst he line and the production line stops!

Andon is not a System for Problem Solving, but it tells you that there is something wrong and you should go to investigate! Andon is not a cure-all against defective products, because everyone can overlook something!

If you are interested in implementing a Toyota like Andon System into your production, you should consider some aspects!

General Aspects:

  • You have to define Standards. The whole System must be stable!
  • You need clear and easy understandable rules in your team!
  • You have to define who is responsible for what!
  • You have to define workstations or workzones!
  • You have to divide the working process into easy handable steps!
  • You need to define WHAT you are going to measure!
  • You have to define WHO has the knowledge, experience and the skill to solve problems?
  • You should implement a System to exactly know, how long the Line stopped (Downtime) and how this affects your Takt Time
  • You have to exactly define the communication between the teamleader and the worker!

The Andon Board:

  • The Layout of the Andon Board must be simple!
  • The Andon Lights should be easy and understandable for everyone!
  • The Andon Board has to be seen by everyone!
  • The Andon Board must show WHERE the problem occurred!
  • The Andon Board must show if the Problem has been solved or not!
  • You can use the Andon Board to show other informations, such as Takt Time, Shift Target, etc.

Andon Board Andon? (the Toyota Way)

a simple Illustration of an Andon Board

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in Buzzwords, Lean

empty gauge Andon? (the simple way)


Whats has Andon to do with the above picture?
Let’s take a look into Andons History! Andon 行灯 in japanese means “Paper Lantern”. Nowadays it is mostly written in Katakana, the japanese “alphabet” for foreign words: アンドン

So please take a look at the picture now. What you see is a gasoline gauge, and the tank is empty. So a light will tell you there is an “abnormality” with your gas tank. And exactly this is Andon!

Andon is a light o audible signal that there is something wrong. Changes in text are  not highly perceptible, but light signals are, even if you are not directly looking at them. Maybe in your car you are are used to see the signal “lights on” and when you leave the car, you forget to turn them off. In most vehicles today, an audible alarm helps you to recognize that you forgot something (or the car turns them off automatically). But I’m shure you will notice the andon light for “fuel empty” as in our example (I hope you don’t see it every day icon wink Andon? (the simple way)

The traffic light at a crossroad is an andon, too! It tells you:

All green > go go go
Yellow > please keep attention!
Red > WAIT! You can’t proceed because “there is a problem!”

Andon just works this way! It is very easy! If there occurs a problem, a light or audible alarm will tell you that something is going wrong.
Even your Keitai 携帯 (Japanese for Cellular Phone) will tell you trough Andon if the battery is alright or not!

Tomorrow we will learn how Andon (and Jidoka) affects Toyotas Production Line. Keep in touch, it is really interesting!

Greetings from Team Arashi

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