Testing with HALT (Highly Accelerated Life Tests) and HASS (Highly Accelerated Stress Screens) techniques has revolutionized product design, reliability and cycle time to market.HALT and HASS subject products to stresses at levels well beyond those expected in normal use until the product fails. With HALT, manufacturers can identify weaknesses in product design and improve product reliability. And with HASS, quality control is tested during the manufacturing process.

HALT and HASS techniques allow electronics manufacturers to accomplish, in as little as a few hours, what sometimes takes days or even months to accomplish with less effectiveness and at a higher cost when using traditional stress testing techniques and technologies.

Highly Accelerated Life Test (HALT) is one of the newer applications of step stress testing, for improving the reliability of a product, before the product goes into full production. In essence, HALT is an environmental step stress test until the product destructs. HALT also precipitates defects, but it is mainly used to identify a product's mechanical, electrical, and design margins, destruct limits and establish the ESS/HASS process values. For the best return on investment, HALT should be used at the prototype and pre-production stage, but it can be used on existing products to improve field reliability. It should be emphasized that HALT in itself does not improve product quality; it must be coupled with an effective corrective action process.