CS 325: Software Engineering January 27, 2015 Domain Modeling Application Domains UML Class Diagrams

Application Domains CS 325 January 27, 2015 Page 44 To assist a software development team in understanding the domain in which a new software application will be employed, domain modeling is used. Business process descriptions Operating procedures Software requirements Business forms Domain-specific terminology Domain-relevant terminology Classes Attributes Relationships UML Class Diagrams Feedback regarding errors & abnormalities

UML Class Diagrams CS 325 January 27, 2015 Page 45 UML Class Diagrams describe a software system’s structure by illustrating its classes, their attributes, and their interrelationships. The diagram at right illustrates several of the principal features of a UML Class Diagram…

UML Class Diagrams: Class Boxes CS 325 January 27, 2015 Page 46 Each class box consists of three sections: the class name, the class attributes, and the class operations. Attributes are analogous to data members (+ is public, - is private, # is protected), while operations are analogous to member functions.

UML Class Diagrams: Associations CS 325 January 27, 2015 Page 47 Relationships between classes (called associations) may have role names and multiplicities defined for each end. A role name is placed at the target class with an arrowhead. A multiplicity indicates how many objects may satisfy the property.

UML Class Diagrams: Generalizations CS 325 January 27, 2015 Page 48 Abstract superclasses and derived subclasses may be represented in UML Class Diagrams. A triangular arrowhead means that one class is derived from another, inheriting public and protected attributes and operations.

UML Class Diagrams: Aggregations CS 325 January 27, 2015 Page 49 Aggregation is the “part of” relationship, while qualification refines the notion of multiplicity. In this example, the diamond-shaped aggregation markers mean that cashier stations are part of branches, which are part of member institutions, which are part of a consortium. Meanwhile, the rectangular qualification marker signifies that while the entire consortium shares each ATM, each ATM is a part of a unique member institution within the consortium. Explanatory comments can be hung from the diagram as notes.

UML Class Diagrams: Composition CS 325 January 27, 2015 Page 50 Composition is the “is-a-vital-part-of” relationship. In this example, the form disappears when the game application is terminated, but not when the game is just over.

UML Class Diagrams: Parameters CS 325 January 27, 2015 Page 51 Parameters can be represented for a class. In agile development, where UML may just be used for sketching a model, this level of detail might be excessive. Note that operation parameters may be given a direction: in (input only), out (output only), or inout (both input and output).