Parametric RDA Folio Plots

Weibull++ includes several plot types you can use to visualize the results of your parametric RDA analysis. You can create plots by choosing Recurrent Event Data > Analysis > Plots or by clicking the icon on the Main page of the control panel.

The following is a description of the different types of plots that can be created in a parametric RDA folio. (For general information on working with plots, see ReliaSoft Plot Utilities.)

Cumulative Number of Failures plots the failure times in the x-axis and the cumulative number of failures in the y-axis. The points represent the actual failure times in the data set and the line represents the expected cumulative number of failures based on a simulation using the calculated model parameters. This gives you an indication of how the number of failures is increasing over time.
Cumulative Failure Intensity vs. Time plots the average rate of occurrence of failures over a period of time. The points represent the cumulative failure intensity calculated at each failure time in the data set and the line represents the cumulative failure intensity based on a simulation using the calculated model parameters. This shows how the rate of occurrence of failures increases, decreases or remains constant for that period of time.
Instantaneous Failure Intensity vs. Time plots the rate of occurrence of failures over several instances of time. The line represents the instantaneous failure intensity based on a simulation using the calculated model parameters. This plot may be used to show how the rate of occurrence of failures has changed at a particular point in time.
Conditional Reliability vs. Time and Conditional Unreliability vs. Time shows the reliability or probability of failure over intervals of time. There are two options:
- Vary Mission Time shows how the reliability or probability of failure would vary over different mission times if the system operated at a specific Start Time. The start time is an assumed value for the system age at the beginning of the mission. For example, a start time = 100 hours means that the origin of the plot corresponds to a system with a total age of 100 hours after a mission of 0 hours. Therefore, an x-axis value of 500 mission hours on that plot would correspond to a system with a total age of 600 hours after a mission of 500 hours.
- Vary Start Time shows how the reliability or probability of failure would vary over different start times if the system operated within a specific Mission Time. The mission time is an assumed value for additional age a system will accumulate during the mission. For example, a mission time = 100 hours means that the origin of the plot corresponds to a system with a total age of 100 hours after a mission of 100 hours. Therefore, an x-axis value of 500 hours on that plot would correspond to a system with a total age of 600 hours after a mission of 100 hours.

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