Experts involved in APAL are defining a best-practice guide for the deterministic and probabilistic assessment of Reactor Pressure Vessel (RPV) integrity. The guide will incorporate improved methodologies and provide recommendations for assessing various types of uncertainties in thermo-hydraulic (TH) analysis, propagation of uncertainties throughout the entire Pressurized Thermal Shock (PTS) assessment, human factor, WRS solutions, WPS methods, etc. These are essential aspects for Long-Term Operation (LTO) of nuclear power plants. The document will summarize the experience accumulated by the professionals in advanced PTS analysis, serving as a valuable resource for nuclear power plant owners, suppliers, regulatory bodies, and other stakeholders. The End-user workshop is organized to inform potential users, foster discussions, and collect feedback to refine the guidance.