Are task cases (essential use cases) different from use cases in UML?
Like most object-oriented notations and methods the Unified Modeling Language (UML) developed by Grady Booch, Ivar Jacobson, and Jim Rumbaugh and now an OMG standard includes use cases. However, it does not formally or explicitly recognize essential use cases. Indeed, the UML does not define or specify the narrative form that defines the contents of use cases. Typically, use cases based on UML are expressed as concrete interactions written in a simple narrative form as a list of steps. As such, they are less effective tools for user interface design and for improving product usability. See also use case relationships; see also actors and user roles. For more detail, see the paper on structure and style in use cases.
