SRC Forum - Message Replies
Forum: Reliability & Maintainability Questions and Answers
Topic: Reliability & Maintainability Questions and Answers
Topic Posted by: Reliability & Maintainability Forum
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998
Posted by: Ken
Date posted: Mon Jun 9 10:07:12 US/Eastern 2003
Just want to clarify Failure Definition and Scoring Criteria is based on the causes of failure or on the end result. For instance if it a system fails due to an operator fault which results in a Mission Abort failure during Reliability Demonstration (RD). Do we consider this failure chargeable?
I just want to sentence these kind of failures fairly because the supplier argue that despite the end result is Mission Abort or Mission Affecting, the root cause is due to human error and not because of design or quality deficiency. Please advise. Thanks
Subject: Failure Definition
Reply Posted by: BWD
Date Posted: Mon Jun 9 11:14:55 US/Eastern 2003
In determining failure cause categories, one needs to consult with the old MIL-STD-781, Reliability Testing for Engineering Development, Qualification and Production. Paragraph 4.7 of the standard defines the categories of test failures. The first decision point is the determination of relevant and non-relevant failures.
Relevant failures are: intermittent, unverified, verified and pattern
Non-relevant are: installation damage, accident, mishandling, test facilities or test instrumentation, overstress conditions, normal operating adjustments, secondary failures, and "Failures Caused by Human Error".
Non-chargeable failures include "NON-RELEVANT FAILURE", so the answer to your inquiry is the human error is non-chargeable as it is non-relevant to the test no matter what the result of the failure.