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Mar 17, 2010

The Fault Tree Analysis Diagram

The fault tree analysis diagram is an important tool for quality management. This visually diagram depicts all the major faults that have occurred in a product.
This enables all those who are involved in the production of a product to be able to understand why these faults have occurred and they can then ensure that the causes of the faults are eliminated.

It can also using in new design process to eradicate faults that have occurred in a product and ensuring that future products are fault free.

One particularly good aspect of the fault tree analysis is that it seeks to get to the root causes of any fault problem, and making certain that they do not happen again.

The Fault Tree Analysis In Action

The first step in creating a fault tree analysis diagram is to identify a specific component that is to be analysed. This will be placed at the top of the tree, in its own individual box.

Next, all the faults that are to be found within the component need to be identified. This can be done through brainstorming to identify the failures.

Faults each have their own box below the component.
It is now necessary to work through why the faults have occurred. What were the causes? What actions resulted in these faults being created?

All the causes for the faults need to be identified and then set out in boxes, each one linked to the faults that are listed.

From here it is necessary to get to the root cause for each fault, which may require listing several causes and then deciding which is the root cause in the sense of deciding which is the cause that can be controlled and therefore can be altered so that the fault is no longer produced. Root causes are then linked to the general causes.

Identify countermeasures. Once all the causes and the root causes have been identified then countermeasures need to be listed. These are the antidotes to the root causes and will ensure that the faults are eliminated. Countermeasures are then linked onto the root cause boxes, because they show the actions that need to be taken.

Benefits Of Fault Tree Analysis
The fault tree analysis is very good at looking at a problem from different angles. It requires a very honest approach in order to get to the root cause of problems that result in fault. So human error has to be looked at and also what caused the human error to happen. Was it the result of staff not caring, staff being pressurised in terms of time, or are there issues of staff training that need to be addressed?

The process of getting to the ‘root cause’ for a fault is often quite lengthy, so the fault tree analysis diagram, if it is to be done properly, has to focus on a number of aspects of the production process. Failure to properly identify the root causes and the countermeasures will result in a fault tree analysis that simply fails to elicit improvements. However, when done properly and the root causes and countermeasures are all listed, this analysis can be a powerful catalyst for improvements to production.