User requirements notation
The User Requirements Notation ( URN ) offers the possibility of specifying a system and defining the requirements for it formally. It is thus possible to check these requirements for correctness and completeness.
URN is a formal description language defined by the ITU-T (Telecommunications Standardization Sector of the International Telecommunication Union ) in the so-called standards ( recommendations ).
A system is represented graphically in URN and contains various relationships between elements.
The main focus of URN falls on requirements engineering with its goals and scenarios.
Notations
A distinction is made between two notations within URN :
Goal-oriented Requirements Language (GRL)
The Goal-Oriented Requirements Language (GRL) is a graphical notation for modeling non-functional requirements ( non-functional requirements ). It enables project requirements to be represented graphically and difficult relationships to be highlighted. It is also possible to graphically evaluate the resulting project plan.
Use Case Maps (UCM)
Use Case Maps (UCM) describe graphically the functional requirements ( functional requirements ) of a software system. They describe precise processes that are similar to MSC diagrams . It is possible to display a control flow and to distribute various tasks to various plug-ins and to assign actors.
Examples
GRL diagram
Associated UCM diagram
Norms and standards
- Z. 150 User Requirements Notation (URN) - Language requirements and framework
- Line 151 User Requirements Notation (URN) - Language definition