217Plus has a built-in database of EPRD/NPRD data. The following explains how to access use it.

For the part, select a “Part Category” of “Other”. Then use the pull down at “Part Type” to select the part description that best matches your part.

Next, select the component’s “Failure Rate” tab. Down under “Component Failure Rate” you will see an empty rectangular data box labeled “RIAC Data”; next to it are two buttons labeled “Source” and “Search”.

Click on “Search”. It will open a window showing the NPRD/EPRD parts that best match your description. You can refine the search by applying the “Quality” and “Environment” filters to select parts that better match your application. You can also use the “Part type level” selection to further refine the search. Once you have narrowed down to the desired set of parts, click on the “Select merged failure rates”. This will close the Search window. You now MUST select the RIAC Data “option button” in order to apply the failure rate to your part.

Circuit Boards – are not modeled by 217Plus (or by Telcordia). 217Plus includes a ‘solder joint’ failure rate term in the component models, which will account for most PCB related failures. However, if you still want to assign a failure rate for a circuit board, select the circuit board part type as ‘other’, then for the part type, select “Circuit Board Assembly, Unpopulated”. You can then apply a failure rate from the RIAC data as explained above.

IGBT – are not modeled by MIL-HDBK-217 – or by 217Plus, or Telcordia or most methods. I model them as being two parts: a MOSFET (to simulate for the input end, or gate) and a Bipolar Transistor (for the bipolar ‘output’).

Hybrids – should be broken down to their discrete elements (capacitors, transistors, etc.) and apply the appropriate 217Plus model to each of the elements. In other words, it should be treated as an assembly of components.

217Plus contains an equivalent to every part in MIL-HDBK-217 that are still used in current designs, either through the 217Plus component models, or its EPRD/NPRD database. In addition, the EPRD/NPRD database has numerous parts that are not included in MIL-HDBK-217.

Paul Wagner
Senior Engineer