The UDS (Users Design Specification) is the design-basis document for ASME Section VIII, Division 2 pressure vessels. It defines the vessel design requirements and serves as the single point of reference for the Manufacturer's Design Report (MDR). Despite its importance, the authors' have observed instances where insufficient attention has been paid to the creation of this baseline document. This paper discusses both requirements and recommended good practices for writing a UDS in accordance with the new Division 2 requirements. The work and information flow to arrive at the required and recommended information is discussed. In particular, the multi-disciplinary nature of a well-developed UDS and the importance of change management will be emphasized. Finally, formatting and other good practices will be discussed.
