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About PDF Plot

The Probability Density Function (PDF) Plot is a lin-lin graph that counts the number of failures between certain time periods, creating a curve that estimates how many failures you can expect to occur at a given number of time units. This graph displays Probability vs. time. The term Probability is used here to describe the percent of the population that failed at the particular value of time (t). A PDF graph helps you to answer a question such as, "What is the chance of a member of the population failing at exactly the time in question?"

The PDF graph shows the curve fit of the data. It answers the question, "Based on the curve fit, what is the probability that failure will occur below or above a certain value?" The graph is a graphical representation of the data that displays the variance or spread of the data.

Note: Interaction with graphs is not available on touch-screen devices.

Graph Features

When you access a PDF graph, GE Digital APM displays auto-censored datapoints that represent the life between the last date of the failure for the given piece of equipment and the end of the analysis.

While accessing a PDF graph, you can:

• Hover or select any datapoint to access the coordinates and the details of a datapoint.
  • For an Estimated datapoint, you can access the type of distribution, the distribution parameters, and the value of R-Squared.
  • For an Observed datapoint, you can access the name and the value of the Variable.
• Select an observed datapoint to access the Point Information window. You can then select Go To Editor to access data.
• Censor a datapoint.
• Customize the appearance of the graph by using standard graph features.

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