This Recommended Practice (RP) defines and describes HALT (Highly Accelerated Life Testing) and HASS (Highly Accelerated Stress Screening). This RP contains information on the philosophy behind the testing, generic examples of tests, the differences between standard testing equipment and equipment used for highly accelerated testing, fixturing considerations, alternative approaches, additional environments, and lessons learned, along with other useful information. This style of testing takes a Qualitative approach (looking for the quality of the design and workmanship) rather than a Quantitative approach (being able to use the results to calculate length of life in service). This RP is not meant to take the place of a test specification but to be used in conjunction with a test specification or as general guidance.