Prediction Parameters
Each model has a set of parameters for each part that it supports. When the selected model supports a failure rate calculation for a part category/subcategory combination, the parameters required for this part are shown in the Prediction Data pane.
The default parameter values for a part yield the industry average failure rate for that part. Clicking Defaults switches between showing and hiding the default values. For more information, see
Defaults for Part Parameters. To calculate a more accurate predicted failure rate for the part, you can enter parameter values that specifically reflect the application of this part within your system.
When the model supports a large number of part subtypes, parameters are shown and hidden based on the subtype selected. When hiding the parameters that do not apply to the subtype, all subsequent parameters are shifted up. Because the Siemens SN 29500 v1 model supports a large number of part subtypes, this shifting of parameters is most evident when using this model. Because the IEC TR 62380 and RDF 2000 models also use parts subtypes, shifting of parameters can also be seen if one of these models is in use.
When the model does not support a part, its
Prediction Data pane displays a message indicating that there is no failure rate model for the part. For more information, see
Unsupported Parts. If a part’s
Prediction Data pane displays a No data required message, one of two situations exists.
• If selections are not yet made for the part classification, category, and subcategory, a No data required message indicates that model support cannot yet be determined.
• If selections are made for the part classification, category, and subcategory, a No data required message indicates that the model supports the part but requires no additional parameters. For this part, the model either uses no part-specific parameters in its failure rate equation, or the model uses a constant failure rate. Clicking Pi Factors opens the
Pi Factors window, where you can view Pi (Π) factors for the failure rate equation and the calculated failure rate. For more information, see
Part Pi Factors. In a few cases, the
Prediction Data pane requires you to select a part type, which the model then uses to identify the appropriate constant failure rate.
To report on the specific part data for each of the assemblies in your system, you can use the supplied Report Design file, Prediction Specific Part Data.
Show units for specific reliability part data specifies whether to show the units for values entered in the
Prediction Data pane. This checkbox appears under
Prediction in the
Options window, When it is cleared (default), units are hidden. When it is selected, units are shown. For more information, see
Prediction User Options. You can also press F1 when the
Prediction Data pane is active because the context-sensitive help topics for parameter entry note the units where applicable.