Telcordia Calculation Methods
In the Calculation Data pane for a MIL-HDBK-217, Telcordia, Bellcore, or Mechanical model, Method indicates whether a Telcordia calculation method is to be used to take burn-in, laboratory, and/or field data into account in the prediction. For more information, see Telcordia Calculation Methods. The method selected for the top-most assembly is inherited by all lower-level assemblies without override selections.
Descriptions of how the selection for Method affect failure rate calculations follow.
• When (No Method) is selected, Telcordia method-related Π (Pi) factors are not calculated for the parts in the assembly and no method calculations are run. When a MIL-HDBK-217 model is selected for the top-most assembly, (No Method) is the default. When a Telcordia or Bellcore model is selected for an assembly or part, a method selection is required. For these cases, the method for the top-most assembly defaults to Method 1 Case 3. This same method is also the default if the following conditions exist:
A Telcordia assembly inherits (No Method) from a non-Telcordia parent assembly.
A Telcordia part is inserted in a non-Telcordia assembly where (No Method) is selected or inherited.
• When Method 1, Case 1 is selected, no fields are available in the Method Data pane because this method does not support taking burn-in, laboratory, or field data into account.
• When a method other than Method 1, Case 1 is selected, the burn-in, test, and/or field data to take into account is entered in the Method Data pane for the assembly or part, depending on the level at which the data has been collected. For more information, see:
The following table lists the methods to choose to make the fields under Burn-In data, Laboratory data, and/or Field data available in the Method Data pane for an assembly.
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Heading
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Methods Making Options Available
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Burn-In data
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Any of the following choices:
• Method I Case 3
• Method II Case L3
• Method II Case L4
• Method III(a)
• Method III(b)
• Method III(c)
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Laboratory data
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Any Method II choice
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Field data
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Any Method III choice
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You can use Telcordia calculation methods with all but the FIDES, IEC TR 62380, and RDF 2000 models. To use these methods with other models, you would temporarily switch the model selected in the assembly’s Calculation Data pane to MIL-HDBK-217, Telcordia, or Bellcore so that Method is shown. After selecting a method, you would then switch back to the original model selection.
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