Viewing Weibull Plots
When you analyze life data sets, Windchill Weibull automatically generates and displays the resulting Weibull plots in the Weibull Plot pane on the right. These plots are updated dynamically as you make changes. So, for example, if you change the distribution, the plot is updated to display the newly selected distribution.
To view the resulting Weibull plot:
1. In the window on the right, select the Weibull Plot pane.
You can learn many things by examining a Weibull plot. For example, if points are concentrated in one particular area, a batch problem might have occurred due to production or assembly processes, maintenance or overhaul schedules, or increases in service usage.
Sharper corners or dogleg bends, on the other hand, might indicate multiple competing failure sources. For example, many components have a high infant mortality due to production and quality problems, and then they have another group of failures later in life when they begin to wear out. In this case, you might want a separate Weibull plot for each failure mode, treating the data points for other failure modes as suspensions. As noted earlier, Weibull analysis is most effective when each data set concentrates on one failure mode.
You can also use the plot to determine if the distribution selected fits your data well. For example, if the failure data points curve in comparison to the best fit line, then the selected distribution probably was not the best fit for the data. To determine a distribution with the best fit, you can perform best fit distribution analysis.
2. Determine the B10 life, which is the time at which 10% of the items in the data set have failed. To do so, place your cursor at the point where the plot line intersects the horizontal line at 0.10 Probability. A tooltip indicates the probability value at a specified time. Your time varies, depending on the random data points that were generated.
 | You can always zoom in on a specific area of the plot by holding down the left mouse button and drawing a selection box around the area you want to view more closely. To reset your zoom, right-click and select Reset Zoom. |