communityUML 2torial 1. Model Elements

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communityUML 2torial

2 Models

A UML 2 model is a description or specification of a system and its environment for some certain purpose. A UML model is composed of model elements, statements about those model elements, and drawings representing some of those elements and statements. It is a representation of some system, existing or to be built.

When the model is a description of an existing system, the meaning of the model is: the system is like this.

When the model is a specification for a system to be built, the meaning of the model is: build one (or many) like this or build something that can make things like this.

When the model is a specification that is part of a standard, the meaning of the model is: a conforming system must be like this or a compliant standard must be like this.

5.1 Model elements

The elements of a model are used to represent what is in the system and its environment.

[ A side discussion on seven distinct and important relationships. ]

UML 2 models are made of basic model elements and statements. Statements are about model elements. Some statements are definitions, defining new kinds of model elements and new individual model elements. Many statements are statements about a particular state of a system (e.g. a snapshot) or are invariants about the system (e.g. the specification of a programming language class).

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