Mumbai University > Information Technology > Semester 7 > Software Architecture.

• UML diagrams are visualizations of more semantically meaningful elements such as classes and statechart nodes.
• UML concepts are mapped to particular graphical symbols. For example: the ‘generalizes’ relationship between elements is mapped to an arrow with a closed, white, triangular head.
• UML is only associated with a canonical depiction and not a canonical user interface. That is, UML designers prescribe how UML diagrams should look, but not how the user should interact with them in tools or editing environments. These decisions are left up to individual tool vendors like Rational Rose, Dia tool.
• The canonical graphical visualization is not the only visualization available to UML users. Although it is not part of the core UML standard, it is possible to visualize UML data using text through the use of XMI.
• XMI is an XML-based format devised to facilitate interchange of models between tools.
• Plain XML encodes only the information in UML model, but not information about diagram layout from graphical visualizations.
• One of the main advantages of UML’s canonical graphical visualization is the consistent use of symbols across diagrams and projects. The rationale behind this decision is that it increases the ability of stakeholders who are familiar with UML to quickly understand the meaning of diagrams in different contexts.

Limitations:

• Symbolic consistency in visualization cannot create semantic precision at the national level. That is if the concept of generalization is semantically ambiguous, the consistent use of the same arrow shape to depict the concept cannot repair this ambiguity.
• Additionally, the use of the same set of symbols across project and domain boundaries limits how much UML can be specialized for a particular domain.