Let’s think about the order of system FMEA and HW/SW FMEA

I got inspired from ECSS-Q-ST-30-02C, and I post it regarding this topic.

I’m not sure how many FMEAs are required, but let’s assume that there are 3 kinds of FMEAs; System FMEA, HW FMEA and SW FMEA.

In this case, which FMEA should be performed at first ?

My conclusion is that System FMEA should be performed at last, and HW and SW FMEA should be  performed at first.

The reason is that FMEA is bottom up approach, and If we consider to begin System FMEA and then perform HW and SW FMEA, it is hard to bridge between System level and lower level(SW, HW).

System FMEA is upper level of analysis, and HW and SW FMEA is lower level of analysis. If FMEA is bottom up approach, then why we do not perform HW and SW FMEA at first?I

What I perceived from my colleagues is that some seem to agree my opinion even though we didn’t do so far, and the others shows their opinion that it is not reasonable; it is not possible.

I don’t want to persuade persons. They really can feel comfortable to do so. So I should not neglect their opinion. Anyway in this situation, I have to set a verification criteria(or principle that they should follow) to keep high quality of FMEA results.

Though I assumed that there are 3 kinds of FMEAs in the beginning, but I don’t like this practice, actually. Maybe I’ll post about this topic in the next.