Andon system - Lessons Learned

I recently had an opportunity to implement an Andon system in my production company. Below are my notes from the implementation process.

Andon is a popular tool used in Lean Manufacturing. It was originally pioneered by Toyota as a method to visualize problems, help create employee's awareness about targets and non-standard conditions, and promote leadership behavior. It is linked with the Jidōka methodology in the Toyota Production system that encourages operators to recognize a deviation from the standard and, by their own decision, stop the line and call supervisors or support staff who can help solve the deviation. In most Japanese factories you will see a variation on the sign「止める・呼ぶ・待つ」- Stop-Call-Wait that reminds operators that this is the expected behavior. Andon is a physical realization of this principle on the shop floor.

In the classic version of the Andon, the operator pulls a signal cord that is located above the working area. The signal cord, in turn, activates a signalling system (a traffic light above a production line, a display board located on a easily visible place on the shop floor, etc.) and this alerts the production personnel about the need to quickly come to the workplace and solve the issue.

But besides signal cords, Andon can take many forms such as signals sent by pressing a red buttons or other custom hardware, using Andon lights similar to traffic lights, using mobile phones with special applications or using laptops or computer terminals on the shop floor. Alerts can be also automatically triggered by the production equipment.

I found the following points useful when implementing the Andon system.

  1. Less is more - when designing the system (how many types of alarms will be used, how will the Andon board look like, etc.), aim for simplicity. It's much easier to explain to users a simple system, so acceptance will be better. If some additional features are needed, they can be added later. On the other hand, with complex system the users will be more confused and some of the features will remain unused anyway.

  2. Explain the benefits - when starting the system, think about all the stakeholder groups that will be affected - operators using the system, team leaders using the Andon board, support departments helping the operators. For each stakeholder group you should prepare an explanation how the system will benefit to them personally in their daily work. This is different than explaining of the benefit for the whole company (e.g. "we will increase the productivity"), because people generally care mostly about a direct impact to them.

3. Integrate with existing systems - Andon should not be a standalone system separated from the rest. Try to think in advance how it can be connected, or how it can replace existing system. The goal should be to remove some waste (non-value adding work) that you currently have. Examples of wastes that can be reduced by Andon include record information into paper documents or physical movement out of the production line to look for support in case of line issue.

4. Re-use existing resources - in line with the lean methodology, even Andon system should be as inexpensive as possible. An optimal system will depend on the size and specific situation and conditions of each company. However, in many cases modern factories already have on the shop floor a lot of hardware that can be used to implement an Andon system, for instance a computer network joining the workstations, computer terminals near workstations, TV display sets or monitor in the production hall. In some cases, it is possible to use this existing equipment to build an Andon system with almost no additional investment.

5. Make use of psychological "nudges" - most important of all, a successful Andon system should be successful in highlighting abnormal conditions to personnel and suggesting to them that the issue should be solved as soon as possible. To this end, there are several tools that can be used.

  • usage or colours - most traditionally, a "traffic light" system is used with green showing a normal condition, yellow means warning and red means alert

  • alarm duration - since we are interested to solve the line issues as quickly as possible, it is very important to visualize the passage of time. Think of some way to display the length of time since the alarm was activated. This alarm duration can also be used to set-up an escalation system - if the alarm runs for a specified amount of time, next level of management will be informed

  • audible signals - Andon systems often show alarms not only visually but also by sound signals. Many factories implement a melody that is played with each alarm - you can hear the signal wherever you are on the shop floor, and as an added benefit you can use a different melody for different production line, allowing quick recognition of where the problem is

To summarize, I found the implementation of an Andon system to be a very stimulating experience and I would recommend to anybody to try to do the same. There are many industrial solutions available (use Google to search for "Andon system" or "Andon board"). If you want to try a lightweight solution, you can try implementing an open-source software Andon I maintain at Github.