NPRD values in FPMM/FPMC [2022R2]

medini_1050701002

Hello everyone, I'm trying to use some values from the reliability catalog NPRD which are in FPMM and FPMC.  When using these values I get that in "expression" (the "x+y" button):   lambda_db = 0.123456;
lambda = lambda_db * undefined;  And I don't know how to input my number or cycles/hour (for FPMC) or my number of miles/hours (for FPMM). Trying to access "lambda_db" in the scaling expression as suggested in the medini help does not work. Playing with mission profiles did not work either. I don't have up to date documentation so maybe it is explained in a more recent version.

medini_1023909254

Hello Gerard, unfortunately we can not support FPMC/FPMM with medini. The NPRD does not contain any information on the duration of a single cycle resp. the duration required for one mile which is the base for the reliability numbers in the NPRD. However, these data actually would be required by medini for a conversion into FPMH (or FIT) to make numbers comparable. Note medini is doing all reliability calculations in FIT - even though the display can be adjusted to FPM or FPH. Due to these limitations medini will show an error message during computation (as the value is multiplied with undefined) and the value NaN for entries based on FPMC/FPMM. The recommendation would be to select an entry which has the same component category (and other parameters) which but has FPMH defined. In general for scaling you would not use lambda but rawFailureRate - which is the result of the formula calculation. As NPRD and EPRD do not provide any formulas for the failure rate determination but fixed numbers, the default mission profiles as they can be used for failure rate handbooks like SN29500, IEC62380 etc. can not be used (resp have no impact on the numbers). Nevertheless: The Environment/Usage factor for the selection of the right category is dependent on the selected Application Factor used for the entry selection. Eckhardt