This document is intended for use by designers, reliability engineers, and others associated with the design, production, and support of electronic sub-assemblies, assemblies, and equipment used in AADHP applications to conduct lifetime assessments of microcircuits with the potential for early wearout; and to implement mitigations when required; and by the users of the AADHP equipment to assess those designs and mitigations. This document focuses on the LLM wearout assessment process. It acknowledges that the AADHP system design process also includes related risk mitigation and management; however, this document includes only high-level reference and discussion of those topics, in order to show their relationship to the LLM assessment process. As microcircuit technology progresses, the risk of early wearout increases for users in the aerospace, automotive, defense, and other high performance (AADHP) industries. There is a need for these industries to have a standardized approach to analysis and testing for wearout, to ensure reliability and durability of future products, and to assess likelihood of early wearout in safety and certification analyses. The standardized approach also is intended to avoid introducing competitive disadvantages to those who address the issue pro-actively and effectively. This revision is being made to (1) revise, correct, and update the wearout acceleration models in Appendix D, (2) remove references to specific wearout analysis software tools in Appendix F (rev original), and revise Appendix F (rev original) to list essential attributes of such tools (and to rename it Appendix E in rev A), (3) to rename Appendix E, mitigation methods in rev original, to Appendix F, mitigation methods, in rev A, and (4) revise and update the language in other clauses to be consistent with subsequent SAE standards work, e.g., ARP6379 and SAE J3168.