Ruby,
To justify using higher levels in MIL-HDBK-217, I used field data to demonstrate that the failure rate was better than the predicted.  Even with this data, the millitary personnel that I was working with required that I show the "unadjusted" prediction numbers.  Proving that your field data is acurrate is a different issue all together.  
Hope this helps,
Brent

>>> [log in to unmask] 09/15/00 06:35PM >>>
Hello all:

Is there any guideline or standard about how to upgrade or identify the
plastic components to higher level in MIL-HDBK-217? For example, , how to
identify the plastic transistor as JANTX quality level? Any qualification
testing procedure, or screening procedure?

Any information are very welcome! Thanks in advance.

Ruby
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