Thanks for getting back to me. I should have clarified before. When I said FITs I should have also mentioned the step of converting FITs to failure rate (10^6 hours).
[I have edited my question to reflect this for future readers]
To clarify my question, I was wondering if it was possible to use 217plus to calculate component failure rate (from MTBF) and use this in the absence of manufacturer failure rate in my existing MIL-HDBK-217F calculations. Usually this would only involve applying the desired temperature and environment factors to the database of failure rates, using these results to generate an overall MTBF for the assembly.
I hope that makes sense…