In the Unified Modeling Language a use case diagram is a kind of improved UML behavior diagram (Chanda et.al, 2009). The Unified Modeling Language (UML) defines a graphical notation to represent use cases called use case model. UML does not define standards for the written format describing the use cases, and so many people do not understand that this graphical notation defines the nature of a use case, but a graphical notation can only give a simple overview of a case or use a set of use cases (Ibrahim et.al, 2010). The use case diagrams ...
