HASS - Highly Accelerated Stress Screen

Highly Accelerated Stress Screening (HASS) is the ideal tool for both qualifying product changes, and monitoring the reliability throughout a products life. Engineering was fraught with poor quality components in the early days, but this is no longer the case, and therefore traditional production screens that originally identified infant mortalities are not as effective as they once were.

As component reliability has increased, the ability to weed out the 'good' from the 'bad', has become more of a challenge. No longer is the line between good and bad as clean cut, there is now a requirement to put these newer, more reliable products through a stronger screen.

Brief Summary

After conducting HALT on your product, and provided improvements have been made where required, your reliability, and confidence in the products performance should be high. The problem is that the HALT was just a snap shot of the products reliability, it only applies to the particular revision of the product that underwent testing.

Every engineering firm understands the need to constantly maintain and update components and software, while every manufacturer understands the requirement to change their process, and or supplier sourcing from time to time. As soon as changes are made you need to know whether the reliability of the product has been compromised.

HASS is a tailor made screening solution for each of your products. Because you have conducted HALT testing, you know exactly what your product can handle. This knowledge provides you with the ability to create a production screen that won't damage good hardware, but will find process related issues, along with supplier discrepancies.

The limits attained during HALT are used to create an effective HASS screen. The process of HASS development will ensure the screen is strong enough to flesh out dormant failures, while running a Proof Of Screen will provide confidence that the screen is not going to damage good hardware.

The HASS screen pictured above is derived through a process of planning, design and practical application of stress. These stages are outlined below: