Possibility to assign a safety mechanism if safety violation in unchecked

Question

Status : rejected  Priority : Major, #12     Schedule : (according to Project Owner)      Current state :not working but this is intended functionality     Critisism on current state : only possible if ticked     Objective of the change : efficient workflow     Proposed change : possibility to assign a safety mechanism if safety violation in unchecked  Original Author : Peter Ploß  SM can only be assigned when "violates safety goals" is checked, assignment should always be possible!  2019-07-23_Ploß: to me this is not expected, as a safety mechanism is active irrespective whether the effect is {safe; dangerous; latent} -- it merely reduces the undetected rate : lambda_undetected = lambda_base * (1-DC)  (e.g. out of range detection of some electrical signal)  2019-12-11 PP with Ansys: medini understood that it is intended to model a failure mode together with its safety mechanisms (SMs, one ore more) and the resulting DC in small fault trees. ZFs opinion is that a SM "acts against" a failure mode irrespective of a Safety Goal and irrespective of the classification (safe; dangerous; latent).   no solution available --> ZF will create a script that brings a failure mode together with the assigned DC_SPF (as a workaround) to the FTA     a parent node: FMEDA, line 28"

medini_1036016653 · Answer

workaround implemented at ZF:  In our FMEDA work we now initially apply a script "FMEDA/prepare b) Safety Mechanisms.js" that prepares each DCFailureMode entry by blindly checking all SPF/MF checkboxes, apart for failure modes named "no effect".