Improving Product Reliability and Software Quality, 2nd Edition

8The Reliability Toolbox

8.1 The HALT Process

Without a doubt, the most important tool available to the product development and manufacturing process is a Highly Accelerated Life Test (HALT). Many other methods have been applied throughout the years to improve product reliability, but the HALT process has become the most effective and fastest method to improve product reliability.

HALT is an accelerated test designed to identify field failures before the first product is shipped. It is a method of applying stresses to a product while still in the design phase, which will reveal imperfections, design errors, and design marginality. After these design issues are identified, they can then be corrected through redesign. The HALT process is then repeated to verify that the design changes worked and that no new design issues resulted from the design changes. The HALT process is very simple, yet few companies have fully implemented the process.

In fact, many companies do not have a reliability program in place. They consider their quality programs sufficient to achieve product reliability. These companies use the traditional approach of product development. That is, products are designed with “checks and balances” in place like design reviews. Design reviews check to verify the design is complete. The design review will verify, for example, that the parts list needed to build the design is complete. The design review may also verify that the material list is in a “standard format,” ...