The Mean Time between Failure (MTBF) is simply the inverse of the failure rate for an exponential distribution while the Failure in Time (FIT) rate is 10^9 x failure rate
MTBF = 1/failure rate
If FIT = 15.1, then MTBF = 10^9/15.1 = 66225165
You can find the FIT rate for FPGA devices in the Reliability Report (PDF).
The FIT rate and mean time between failures (MTBF) information for devices within the same family with the same process technology will be very similar and can be used for devices not explicitly listed in the Reliability Report.
For FPGA products: Reliability Report is made and uploaded into Resources and Documentation Centre (RDC). Refer to below link.
Please get back to me if you have any other doubts.
We do not receive any response from you to the previous question/reply/answer that has been provided. This thread will be transitioned to community support. If you have a new question, feel free to open a new thread to get support from Intel experts. Otherwise, the community users will continue to help you on this thread.