What is the ANDON SYSTEM

The Andon System tells us whether a machine operates within acceptable effectiveness values. Each OEE calculation in the OEE calculation screen (Summary tab) has an Andon signal. Based on the settings in MASTERDATA – MACHINES  columns Red% and Green % the OEE Andon signal colors red, green or yellow.

Moreover, you will find the Andon System in the various charts (See group:  Analyze-Report Data).

OEE summary screen with Andon signal

Andon color	Function
Green	OEE higher than usual. There were certain conditions that we would like to repeat.
Yellow	OEE within normal range: we strive for GREEN.
Red	OEE lower than usual. There were certain conditions that we would like to prevent from occurring in the future.

How to use the Andon System

Most charts in the OEE Coach are primarily meant for personnel on the shop floor, whereas the Production Andon is, in first instance, meant to be an instrument for the factory management.

In addition, the chart may be used to balance the production lines in situations where they are connected, or for the implementation of Flow Management and/or Lean Manufacturing.

Managing the Team

Work Cells, Process Teams, Task Teams; these units all have one task at hand. A manager who supervises several teams may use the Andon in his daily management activities. Every day he generates the Production Andon over a time period of one day.

Between the teams and management the following way of reporting can be agreed: if the Andon is yellow, the machine is operating on an acceptable level, but if the Andon is either Red or Green the team reports the reason and what needs to be done to prevent or sustain that situation to the management. 

Red Andon report

Questions to be answered in a Red Andon report:

1. What happened?
2. Why did this happen? (Use 5 x times Why analysis)
3. What action must be taken to ensure that this will never occur again?

Green Andon report

Questions to be answered in a Green Andon report:

1. What happened?
2. Why did this happen? (Use 5 x times Why analysis)
3. What action must be taken to ensure that this will always be the case in the future?

Line Balancing;

V-shape

Some production lines have a consciously built-in bottleneck; an expensive component surrounded by several auxiliary installations (e.g. bottling plants).

In order to prevent the main component from coming to a complete stop, it has deliberately put in the production line as a bottleneck by assigning the surrounding components with a higher capacity. By assigning the machines the same sequence number in which they are located in the production line (drag and drop the order of appearance in the table Machines), and subsequently by showing the Production Andon based on order of appearance, the report will show whether the bottleneck is indeed located where it should be.

Equal components

In a production line with several machines there exists often a difference between the theoretical bottleneck and the actual one. If the machines all use the same Standard speed for calculating their OEE and, subsequently, are placed beside each other in the Andon screen, the chart will show where the actual bottleneck is located. By subjecting this machine then to further analysis, such a bottleneck can be solved effectively, which, in turn, will allow the overall production line to perform better.

Using the Andon Settings (in Machine Master-table) to steer Continuous Improvement

The values for triggering the Andon system (which are being set in the machine-master table) are gradually changing while the machine makes improvements. For a start is could be a rule of thumb to set the Green value somewhere near your Best Practice.

So if the average OEE is somewhere around 35%, but once in a while you encountered values like 46 or 48%, the green value might be 45% meaning: ‘We did that once, we are going to try to do it always’.

CAUTION

The red value then could be set just below the average, lets say at 30%. Explain your operators what you want to achieve: First stabilisation of the OEE,  then growth.

So first of all the red light should occur less en less and than the green one should become the daily routine.

After the process becomes at a more or less stable level, i.e. the OEE is always between 45 and 55 % you might want to use the Andon in a different way. It than may become an indicator for a higher autonomy of the team. The team operates the machine and only reports when either the red or the green Andon occur. Red meaning: An abnormality occurred which needs to be prevented and eliminated for once and forever. A group activity could be triggered to solve the root-cause and adjust the system so this incident can not re-occur. On the other hand when the green Andon shows up, an incident or ‘abnormality’ occurred that is most wanted! Also in this case you may want to analyse what happened and look for a way to make this ‘incident’ common practice!

So in case of a red Andon the approach is: ‘It happened once so it can and will happen again unless we make sure to take away the root cause of the incident’ In case of a Green Andon, the approach is: ‘If it could happen once, it can happen twice so we can make it happen always.’

See also: ANDON Analysis