One of the pillars of lean thinking is Jidoka. Lean Lexicon defines Jidoka as “Providing machines and operators the ability to detect when an abnormal condition has occurred and immediately stop work. This enable operations to build in quality at each process and to separate men and machines for more efficient work.” Within Jidoka, andon is the visual management tool used as the signal to call for help and stop production when that abnormal condition is recognized.
Some of the requirements for this type of visual management include
- Standardization – the process must have a standard so that the operator or machine knows when an abnormal condition exists.
- Easy to understand – the signal must be easy to understand without too much training. If it gets to complicated people are spending more time figuring out what the signal means than improving quality.
- Commonly used – the system must be commonly used within a work group. If only a few people in the group are using it, it will not be effective.
- Standard responses – when the signal is indicated those responsible for correcting the issue must know how to respond to avoid confusion and reduce downtime and waste.
I tend to think of andon as the worker on a factory line pulling a cord to stop production, but it can also be an automated system or in an office setting. As I was preparing a teachback on andon for a department report out the office printer started beeping and blinking. I immediately got up, glanced at the screen and grabbed a new ream of paper to put in. When I got back to my desk it hit me that this was an example of andon. The printer encountered an abnormal condition (out of paper), stopped production (my print job was on hold), and indicated the problem through the flashing light and beeping. On the screen is exactly what the problem is and the steps you would need to take to correct it.
Another example of an automatic andon is the low fuel light on your vehicle. The light is the indicator and you, as the operator, know you should go to the gas station and fill up the tank to correct it. There are more examples of andon around us than my originally narrow view of them thought!