The mFMEA Difference
Generally a system FMEA is focused on functions. A Design FMEA might go into more detail. A Process FMEA will mitigate manufacturing risks. A FMECA adds a "C" for criticality, which is part of the standard FMEA and not even in every FMECA (yes confusing).
An mFMEA is a system design FMEA that is focused on functionality at an early stage of a program. That is when it is easiest to make changes to eliminate or reduce risks.
Why so many standards?
Tedious to reduce Disappointment
The first FMEA was created before most engineers were born (1949). The level of effort is often large and the results can be underwhelming. The final system may cost more to develop than budgeted, hit the market late, and be plagued with issues. This has driven establishing standards and requirements to force engineers to "do it right" assuming more diligence will lead to better results. To be fair any FMEA that drives changes will have better results than skipping one completely, doing it too late, or doing it poorly.
How is an mFMEA different than standard methods?
Relentless focus on effort that lead to improvements
As soon as a step of the FMEA process won't lead to a change it is skipped. This will mean some subsystems get no FMEA, and many cells within the FMEA are left blank. Changes proposed that won't reduce the risk enough are rejected to encourage larger improvements rather than continue with a modest improvement that may require more changes again later.
How is an mFMEA similar to standard methods?
Keep what works
A table in a spreadsheet is a fantastic way to quickly capture expert ideas. Experienced engineers have seen how things can go wrong and can imagine even more. Scoring severities and probabilities to get criticality rankings help prioritize risks. The highest risks can be reduced with changes to the requirements, system, design, process or tests.