The Assumptions and Constraints Viewpoint provides a dedicated architectural placeholder to explicitly identify and document the assumptions and constraints that a digital solution analysis and design are based on. The purpose of this viewpoint is not to define predefined or architecture-agnostic assumptions or constraints, but to ensure that users of EIRA or eGovERA consciously articulate the conditions, limitations, and premises that influence their solution design. By making assumptions and constraints explicit at architecture level, this viewpoint supports transparency, contextual understanding, and informed use of the reference architecture when analysing and designing digital public services.