Split an Analysis Into Segments

A Reliability Growth Analysis may, in some cases, indicate that your data is trending in an undesirable direction (e.g., failures are occurring very often, costs are too high). In these cases, you will probably decide to make significant adjustments to your work process to improve the results. You can create a Reliability Growth Analysis that is split into segments to represent periods of time before and after you made changes to improve the reliability of your equipment and locations.

When you generate a report for an analysis that has been split into segments, the report will contain information about each segment and the analysis as a whole.

Steps

Access the Reliability Growth Analysis that you want to split into segments.
In the left pane, select the Cumulative <Measurement> Plot tab.

The Cumulative <Measurement> Plot appears in the workspace.

Note: You can also split an analysis into segments via the Mean Time Between <Measurement> Plot, and <Measurement> Rate Plot tabs.
In the upper-right corner of the workspace, on the Cumulative <Measurement> Plot, select the datapoint that represents the last measurement recorded before you made a significant change to your work process.

The Point Tooltip window appears.
Select Split.

Note: The Split option is enabled only if there are at least three datapoints to the left and to the right of the datapoint you selected.

The plot line bends at the datapoint you selected, representing two segments instead of one.

Although the analysis still has an overall Initial and Final MTBF, each individual segment now also has its own Initial and Final MTBF. The AMSAA Reliability Growth Model page for an analysis based on event or an analysis not based on an event will also display different information for each segment. Each segment is colored according to whether it passed the GOF test. If the segment is blue, it passed the GOF Test. If the segment is orange, it failed the GOF test.

Note: When you split the analysis manually via the Cumulative <Measurement> Plot tab, the MTBE Trend Plot and <Measurement> Rate Plot tabs will also reflect the split.