Highly aggressive life testing ― or HALT, as it is often known ― is a test method aimed at discovering and improving weak links in a product during the design phase.
HALT is a discovery test as opposed to a compliance test. This means the goal is to find problems, doing everything necessary to find and then remove the weaknesses.
In HALT, every stimulus of potential value ― temperature, all-axis vibration, humidity, UV, radiation, etc. ― can be used under accelerated test conditions during the development phase of a product to find the weak links in the design and fabrication processes. Accelerated stresses in combination (e.g., high temperature ramp rates and all-axis vibration levels together) are necessary to compress or minimize the time to failure.
For more information, see the related feature article, "How to Reduce Warranty Costs Attributed to Temperature Sensors."