The hierarchical tree structure in the Derating Definitions pane reflects the derating records inserted in the Prediction Derating file for various model/category/subcategory/type combinations. The highest level represents the calculation model. The next lower level represents the part category. The lowest level represents the part subcategory and type as well as the parameter for which derating criteria are specified in the Derating Data pane. In the Remarks column at the lowest level, you can enter any notes or comments about the derating record.

Clicking < Click here to insert a new record > in the last table row inserts a record. For more information, see Inserting a Derating Record. You must specify a valid calculation model, category, subcategory, type, and parameter in the Add Derating Record window that opens. Under Prediction in the properties for the Prediction Derating file, Default model for new records specifies the default calculation model. For more information, see Prediction Support File Properties. However, in the Add Derating Record window, you can select from any licensed model.

The parameters available for a part depends on its model/category/subcategory/type combination. You might need to specify values for quality level, ambient temperature, junction temperature, operating power, operating voltage, operating current, voltage stress ratio, current stress ratio, and/or power stress ratio. If the part does not participate in derating, only a default parameter is available. Choosing this parameter does not affect derating analysis.