At the moment, many companies assess reliability using MIL-HDBK 217F but I assume FIDES will yield more accurate reliability assesments.
Some equipments are mainly in deep storage and they only fly a few hours during their life. Therefore, it is important to have a good assesment of reliability during deep storage (ground benign condition).
Do you have enough results to compare MIL-HDBK 217F and FIDES assesments of equipments in deep storage to "real" reliability ? I know, it is very difficult to estimate operational reliability since it is random process and we only have confidence bounds for reliability...
Thanks a lot for this website and this wonderful tool that FIDES is !
Charles
Dear Charles,
Thank you very much for your encouragement!
Deep storage is the main concern for the reliability of most missile systems. Non-operating time is also important for a lot of others products, for exemple automotive. Therefore the FIDES Guide has been developped to be also applicable for storage and non-operating conditions.
Comparison has been made between an adapted use of MIL-HDBK-217 dedicated to storage (a proprietary methodology from a FIDES Group member based on field return) and a FIDES prevision. The results confirm that FIDES is a good reliability prevision tool for storage conditions.
The main physical contributors to failures in storage are not the same than in operation. Therefore the definition of the use profile should be done carefuly, especialy for humidity, thermal cycling and vibrations.
Regards,
Lambda
Dear Lambda (I love this name !)
It was not in my intention to offend FIDES community claiming that FIDES was not suitable to assess deep storage reliability... Actually, the individuals in charge of reliability have a few possible methodologies ; among them, MIL-HDBK 217 and FIDES now.
These two methodologies will not yield the same result and companies usually will not spend time and human ressource computing the result with both of them. If fields resuls tend to prove that results are more accurate using FIDES than MLI-HDBK 217, it would be easier to ask them to use FIDES.
Once again, an equipment in deep storage only knows a few failures (hopefully !). Do you have such results ?
Regards,
Charles
Yes, a field return coming from missiles in deep storage has been used to validate the FIDES prevision for storage conditions. This field return was previously used to adjust predictions of former methodologies to non operating conditions.
Lambda