Mission Profile Confusion

Question

Hi,     i'm a little confused about the use of the two different mission profiles (internal working cycles vs. working phases) in the failure rate calculation.      So far, we've only been using the "internal working cycles" part of the mission profile in combination with SN29500-based calculation.     For a new project, we've received more detailed Mission profile data, which has me inclined to use the "working phases" part, but this part of the mission profile apparently is not used by the SN29500-based failure rate calculation (the parameters Teta_u and deltaTeta are not updated in the parameter list of the components).      I interpret the description on the new online help page (https://ansyshelp.ansys.com/Views/Secured/medini/v24202/en/medini_analyze_ug/sec_reliability.html#sec_mission_profiles)   as follows:   the medini mission profiles are specifically designed for IEC
          62380 or FIDES Guide because detailed data is required by these  the mission profiles should be usable also by SN29500-based calculations           But as i wrote above, working phases are apparently not used by SN29500-based calculations. Is the description on the online help page wrong in this case?

medini_1023909254 · Accepted Answer

Hi Lukas,     the SN29500 does not by it's nature any mission profile at all. Medini does enable this by accessing the data from the Working Cycles and calculating a weighted average of the failure rate for the different temperature regions.  In addition you may also use the information  from the Working Phases as variables in a scaling expression. Nevertheless, you need to know how to bring this in SN29500 calculations an I am not aware of a good strategy here. Note, scaling is applied after calculating the failure rate (i.e. the weighted average can be scaled)     Eckhardt