Forum: Reliability & Maintainability Questions and Answers
Posted by: Chang-Ho Lee (firstname.lastname@example.org )
Organization:Korea Aerospace Research Institute
Date posted: Mon Sep 18 21:53:32 US/Eastern 2000
Subject: Reliability Training Courses
I'm reliability engineer taking part in space project in Korea. But I don't have enough experience in space product reliability (Reliability Design, Reliability Prediction, FMEA, Space Environment Consideration, etc.). Could you suggest any short term training course or other training opportunity? thanks.
Posted by: Henry Davis (email@example.com )
Date posted: Mon Sep 18 19:11:53 US/Eastern 2000
Subject: Single Bit Error Rate
There is a requirement that the single bit error rate for memory shall not exceed 25 per one million hours. The SBE shall be calculated using MIL-HDBK-217F, CN2. I also have information re environments, etc. The operating environment is 1 hour/day at 60,000 feet and 23 hours/day at sea level. For sea level I calculated FR based upon 217 and used the Failure Mode Distribution (FMD-91)information for a factor for failures from data bitlosses. Does anyone have any suggestions for the SBE calculations/derrivations at 60,000 feet? If so I plan on taking a weighted average of the numbers for the final calcualtion.
Posted by:Jim Guzzio (firstname.lastname@example.org )
Organization:General Dynamics ATS
Date posted: Mon Sep 18 10:44:01 US/Eastern 2000
Subject: "Merged Failure Rate" Calculation
With respect to the "RAC Data Failure Rate Selection Screen," the User is only able to filter on the Part Type First, Second and Third-Level Modifiers, i.e., there is no provision for filtering on the absence or various combinations of these modifiers. Since the User does not have the ability to select just those rows in the table which he/she wishes to retain for determining the "Merged Failure Rate," it would be helpful to have the ability to perform this task externally. Unfortunately, the methodology required to do this does not appear to be contained in the documentation.
Posted by: Kang
Date posted: Fri Sep 15 14:52:13 US/Eastern 2000
Subject: Quality Factor in 217
Is there any guideline or standard about how to upgrade or identify the plastic components to higher level in MIL-HDBK-217? For example, , how to identify the plastic transistor as JANTX quality level? Any qualification testing procedure, or screening procedure?
Thanks in advance! Kang
Posted by: Sheila Prather (email@example.com )
Organization:Northrop Grumman Corporation
Date posted: Mon Sep 11 13:34:43 US/Eastern 2000
Subject: Operational Parameter Translation
Is there an update to the the operational parameter translation method and/or translation factors published in both the Reliability Engineering Toolkit (dated 4/93) and the Commercial Practices Edition? Both documents reference TR-89-299.
As always, you inputs are appreciated.