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: Benjamin
Date posted: Wed Jul 7 5:57:12 US/Eastern 2004
Subject: Tests : HALT, HASS, Qualification
I'm a french student and I work on the HALT (Highly Accelerated Life Test). I have two questions :
--> what sort of informations give the HALT tests to start creating the HASS tests ? (specifications, etc.)
--> if the HALT tests were realised, what is the development of the Qualification tests (life test during 2000hours, etc.) ? Are they completely removed or just simplified (less hours, stress less rugged, etc.) ?
Very many thanks.
Subject: HALT/HASS Testing
Reply Posted by: bwd
Date Posted: Thu Jul 15 13:24:22 US/Eastern 2004
The HALT test concept is one that uses extreme destructive stress levels to determine some type of design integrity. The test is designed to increase the stress levels until failure occurs. If a large sample is used, you can evaluate the time and stress levels to failure to get a distribution of the events. The HASS test would then use a safety margin, that, a stress value below the fail point, so that the units are not destroyed. Qualification tests are different in that these tests are performed at or below the design limits so that overstressed failures are not encountered. The design limits are much lower that the destruct levels. The test times for qualification tests are generally longer and “less rugged’ than the destructive HALT/HASS tests.