Safety mechanisms copy from FMEDA1 to FMEDA2 based on same CAUSEs

Question

Hello I would like to create a script which would copy assigned SMs from FMEDA1 to FMEDA2 based on same causes inside FMEDA etries.

I managed to put together the code for selection of FMEDA source and FMEDA destination, but that I have chalenges already with read causes from source FMEDA and destination FMEDA.

Apprishiate for any advice for progressing scripting. Ovously I am very fresh/new in medini scripting.

Regards, Klemen

medini_1066019734 · Answer

Dear Eckhardt,

You are right. But I see as connection point between component FMEDA and signal FMEDA still causes and not failures, assuming "what is cause for the failure?".

In same way as for components failures (open, chort, drift) we defined failures of the signals (always low, alweys high, incorrect value) since failures has the same cause (for example "overvoltage pulse") we can assign SM (for example "over voltage protection") to component failure and signal failure.

Best regards, Klemen

medini_1023909254 · Answer

Hello Klemen,

but the Safety Mechanisms are assigned to the component failures and not to the causes of these failures - in fact you would in FMEDA not care about the causes at all (these are only relevant in DFMEA, where you look at systematic failures).

Eckhardt

medini_1066019734 · Answer

Dear Eckhardt,

Thank you for your replay.

FMEDA1 and FMEDA2 are derived from same hardware archeticures but from two diferent System/Function Models. Meaning first system/function model called "WH BOM" contain el. components (BOM), second one called "HW signals" contain all the signals which connects el. components (netlist). Both of them has their own failures, for components are based from component library (FIT (based on SN29500) + Failures(MIL HDBK 338B)).

FMEDA1 is derived from "HW Signals" and FMEDA2 is derived from "HW BOM".

Nowerdays we go over  both FMEDA separatly, defining causes, Effects and corisponding safety mechanisms.

I see that we can benefit in consistency, since team perfomring analysis can do mistakes, in case we deive/copy SM based on causes, which are common, of FMEDA1 to FMEDA2.

BEst regards, Klemen