scope:

This Recommendation defines the User Requirements Notation (URN) intended for the elicitation, analysis, specification and validation of requirements. URN allows software and requirements engineers to discover and specify requirements for a proposed system or an evolving system, and analyse such requirements for correctness and completeness.

URN combines modelling concepts and notations for goals and intentions (mainly for non-functional requirements and quality attributes) and scenarios (mainly for operational requirements, functional requirements and performance and architectural reasoning). In particular, URN has concepts for the specification of goals, non-functional requirements, rationales, indicators, behaviour, scenarios and structuring.

This Recommendation focuses on the definition of an abstract syntax, a concrete graphical syntax, and an interchange format for URN. An assessment of conformity of the current URN representation to the language requirements for URN [ITU-T Z.150] is also included.

URN is applicable within standards bodies and industry. URN helps to describe and communicate requirements, and to develop reasoning about them. The main application areas include telecommunications systems, services and business processes, but URN is generally suitable for describing most types of reactive systems and information systems. The range of applications is from business descriptions of goals and requirements to high-level design.

URN is a notation that complies with [ITU-T Z.150]. It includes concepts and notations satisfying the language requirements of Z.150's URN-NFR (for non-functional requirements) and URN-FR (for functional requirements). URN integrates these concepts and notation into a single language.