The FMEA Pareto built-in view supports a classical method of prioritizing among potential causes of failure in a system, based on the RPN value (Risk Priority Number). The view collects all Causes (Potential Cause of Failure), in all sub-projects and all included FMEA, and lists them according to their associated RPN values in a Pareto chart (http://en.wikipedia.org/wiki/Pareto_chart). This article describes how to use the view.
The view is available when you select a FMEA item, or a Project (a.k.a. "Work Area") that includes one or many FMEA.
Getting Acquainted with the View
In the chart, each histogram bar represents a specific Cause, with its height representing the RPN value (between 1 and 1000), arranged with highest values to the left, and decreasing values to the right.
The RPN scale (to the left) automatically adjusts to the highest RPN value in the collection, while the cumulative percentage scale to the right always goes to 100%.
The blue Percent line in the chart integrates the contribution to the total 100% of RPN values in the collection.
The red line in the chart indicates the threshold value. All Causes in excess of this red line are colored green.
The chart can show any number of causes, and the presentation style and amount of details will adapt to available window size:
Modifying the Threshold value
The Cut-off box contains the Pareto threshold value for the chart expressed in %. The default values is 80. To modify this value, enter a new value and click Redraw.
The red line in the chart will adjust along with the bar coloring if applicable, as described above.
Finding Items in the Structure Tree
When you click on any of the Cause bars, its corresponding location in the structure tree will be indicated in green as shown in the below example.
If any changes are made in the structure tree, e.g., a change to Occurrence or Detectability attributes on a Cause, you will need to press the Redraw button to refresh the chart.