This report identifies, prioritizes and addresses technology gaps in the ASME Pressure Technology Codes and Standards. A key component of this project was to review an extensive selection of current Codes and Standards which relate to power boilers and develop guidelines for component design and flaw acceptance criteria. The main focus of this project is to evaluate the current state of understanding with regard to creep-fatigue interaction for intended boiler materials to support the development of effective Design-By-Analysis (DBA) rules.