Data Set Calculations
In the System file properties, Auto-Calculate data sets checkboxes control whether calculations run as you enter data and parameter values for different types of Weibull and ALT data sets.
• For the Weibull module, this checkbox is located under Weibull and is selected by default. It applies to three types of Weibull data sets: parametric life, non-parametric life, and reliability growth. This checkbox does not apply to warranty or degradation data sets or to parametric life data sets where Competing Failure Modes is selected as the model. For these Weibull data sets, you must always initiate calculations. For more information, see Weibull System File Properties.
• For the ALT module, this checkbox is located under ALT and is cleared by default. It applies only to ALT data sets. For more information, see ALT System File Properties.
When Auto-Calculate data sets is selected, a data set to which it applies is calculated as you enter data and parameter values. Because an auto-calculation runs in a separate thread, the user interface remains functional. While an auto-calculation is running, you cannot start a standard calculation from the Calculate window. In the lower right corner of the status bar, a Calculating message indicates that an auto-calculation is in progress. A flashing button for canceling this calculation is also present. Clicking it stops the auto-calculation. If during the auto-calculation something happens to trigger a new auto-calculation, it is started once the current one finishes. The data set selected at the time that the new calculation starts is the one that is calculated.
When Auto-Calculate data sets is cleared, or to calculate a data set to which this checkbox does not apply, you click Calculate in the title bar of any of its Parameters panes.
Optionally, to calculate either the active data set or all data sets, you click Calculate in the standard toolbar or press F8. When the Calculate window opens, you complete the module’s property pages. For more information, see:
For a data set that is analyzed parametrically, you can view results in any of its Parameters pane. Once results are calculated, they are shown under Calculation results in the lower portion of these panes.