Failure rate distribution to failure modes done differently for permanents and transients - please consolidate!

Question

Permanent failure rate for a model element is distributed to multiple failure modes by column "Distribution (in %)" on tab "Failures" in the properties view of the element. See attached screen shot "distribution_of_permanent_failure_rate_to_failure_modes.jpg".     Transient failure rate for a model element is distributed to multiple failure modes in individual popup windows "Transient Failure Prediction" for each failure mode. See attached screen shot "distribution_of_transient_failure_rate_to_failure_modes.jpg"      Why are the approaches different for permanent and transient faults? Particularly the approach for transient faults requires opening a popup for every individual failure mode. This is tedious and makes it very difficult to check whether sum = 100%.  Proposal: Represent the distribution of transient failure rate to failure modes of a model element in the same way as it is done for permanent faults - directly in nthe table of failure modes.

medini_1055920722 · Answer

Is there a way to just display distribution (Transients Failure Rate Distribution) in a column (separate column will work to)?

medini_1036867805 · Answer

One more comment:  Yes, as you describe, I can imagine, that the distribution of raw transient failure rate on distinct failure modes can be displayed as an additionally scripted property in the failure mode table. But rather, I'm proposing to have that value entered directly in the failure mode table, exactly same as for permanent failures.

medini_1036867805 · Answer

Hi Eckhardt, thanks for the answer.  The different ways to calculate a model element's raw rate of permanent faults (top down distribution) and raw rate of transient faults (bottom up addition) and the rationale for it are clear. That's not a problem.     I'm more talking about the phase after these rates have been determined, i.e. the safety analysis itself. For defining functional failure modes of a model element it is not relevant in which way the rate of faults was determined. So it would be better if the according view would not unnecessarily depend on that.  Sometimes the person determining the raw rates (e.g. design backend engineer) and the person conducting the FMEDA (e.g. a system architect) are distinct persons. Why should the system architect then still care about the different ways to determine raw base failure rates. This step should have been concluded by design import and allocation done e.g. by the design backend engineer. For the task of the system engineer to define failure modes, their distribution and assignment of safety mechanisms, it doesn't play a role any more how the rates were determined. In contrary, this information from previous step might even confuse the next step.  My proposal is to display the distribution of raw rates to IP failure modes in the same way, no matter how the raw rate was calculated. This would be a cleaner separation of steps.  Rolf