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: Bahman Kaboodrangi
Date posted: Thu Jan 6 16:45:19 US/Eastern 2000
Subject: Base Failure Rate for Switches Notice1 vs Notice2
Why is the Base Failure Rate (Lambda B)for Switches in Notice 2 is worse than Notice 1. Please provide reason for the difference between the two versions.
Subject: Switch Failure Rates
Reply Posted by: Bruce Dudley
Organization: Reliability Analysis Center
Date Posted: Wed Jan 12 10:34:42 US/Eastern 2000
In 1992, the Rome Laboratory published a technical report called: RL-TR-92-197, Reliability Assessment of Critical Components, which contains the models and failure data used for the Mil-Hdbk-217F notice #2 switchs. The reason that some switches such as "toggle" switches increased is, the data for the original model was based on a small sample that had few failures. The new model is based on a far larger data base that had numerous failures; therefore, the new model is more realistic to the current operations. The most realistic data is actual historical test data on the part you expect to use. If you have such a data base then it would be your best source.