The UML Workshop. Modelling of Business Functionality and Software on the Basis of the Modified Structure of Requirements Levels
More detailed than the widely known levels of K. Wigers view of the functional requirements is proposed and in accordance with which both functions of the subjects of the business system, including non-users of software, and functions of the software system responsible for its business logic are modeled.
Detalization concerns primarily the functional requirements level and includes variant of classification of software functions, which is connected with their availability through the graphical user interface (GUI), that in its turn allows better separation of software functions aimed at execution of the business logic from GUI functions. The advantages of the practical use of the modified level structure are explained with the help of specific examples. Moreover, new method allowing development of a model of use cases with level detalization to functional requirements is proposed.