What is Andon in Lean?

What is Andon in Lean?

Andon, in Japanese meaning literally a paper lantern - 行灯, is a signal used to alert Lean teams of an important status change, an activity that has failed or is running sub-optimally.

An Andon can be a light going off, a text display on a ticker board, or a sound alert. The important thing is that it is automated since manually triggered signals are too easy to fail and that it attracts workers’ attention. The point of an Andon is to alert the team to immediately stop what they’re doing, and go fix the problem.

Key benefits of using Andons:

  • Higher process transparency leading to better efficiency
  • Fewer defects, less downtime adding up to less waste and lower cost
  • Increased product quality, creating happier customers
  • Workforce that is empowered, happier and less prone to an exchange, producing higher product quality and maintaining process stability
  • Encouraged creative and quick problem solving, which while valuable in and of itself, can also lead to original, unorthodox product solutions
  • Much like Poka-Yoke, using Andons helps to orient the team on quality and fosters the habit of giving quality priority above all else

Andons in everyday life

We encounter Andons in everyday life, e.g. when an engine warning light flashes on the dashboard, signaling an issue with the car, which may force us to drive to the nearest service station to get it resolved. Andons are also widely used in stores, bank or post office queues, and any customer service-oriented teams - and we’ll get back to those later.

In tandem with Jidoka

At Toyota, Andon devices tied in with the company’s philosophy of Jidoka: the automation of problems and defects detection. It meant that if anything on the production line went wrong, the line would be stopped and the defect would need to be resolved right then and there.

Jidoka emphasizes that a problem is fixed at its source, hence a well-implemented Andon should alert you exactly at the time of a problem occurring, and - if possible - at the exact place where it’s happening. Andons philosophy fits in with Kanban’s principle of workflow visualization, allowing teams to get a clear indicator of something going wrong and needing to be fixed.

In Western society, we’re sometimes so focused on wanting to put our best foot forward, that we may be willing to sweep any problems under the rug. The latter concept is frowned upon at Toyota - if there are any problems on the production line, then everyone will be aware of it, and teams will often swarm to do a root-cause analysis and sort out the issue.

Andon must be tied to the Value Stream

Agile software teams are known for the heavy use of Andon devices. You will often see red, orange, and green indicators on build servers used to compile and test code. If there’s a failure on a server, developers are encouraged to stop what they’re doing and fix that problem first.

But what we’ve seen is that the application of Andon is not as easy as it can appear. In many cases, teams are being alerted to activities or events that they would not regard as important at all! For example, there might be an Andon that warns of low disk space on a build server, with orange light flashing - but to a developer concerned with getting their code done on time, this may not seem that important, and they will simply ignore it, and stand the risk of making this a habit.

In some supermarkets or banks, lights are indicating the average queue waiting time, but in most of such cases, you can see that leadership has not trained staff how to resolve the issue - so that the Andon becomes just an indicator of bad service, rather than signal marshaling teams to fix a problem. Unfortunately, such implementations have missed the point of Andon completely.

Were these supermarkets using Andon right, then whenever the waiting time estimation lights up as orange or red - more check-outs should be opened to help with the number of customers waiting for service. Their Value Stream is in people getting through checkout and out the door, not in people observing a stagnant queue with flashing lights in front of them.

Andon won’t work in command and control environments

Andon can be a lifesaver or a bell of foreboding - which it will be for your team depends on the culture that stems from leadership. If management encourages workers to come forward with problems, so that they can be resolved, then Andon will work wonders. But in uncompromising command and control environments, where there’s no room for error or malfunction, we’ve seen teams go as far as to unplug their Andons. When asked why they did this, they explain that the thing just causes management to panic and they get into trouble.

Now, unplugging the Andons does not remove the problems, it only removes a part of the story from management, causing miscommunication, deepening lack of trust, and misaligning all performance metrics, which are missing data of errors having been resolved as part of the process.

Use Andon the right way and don’t waste a great opportunity to get to know your process and the team better - both of which are necessary to perfect and continuously improve production.