The Basic Association of UML



First , a Dependency is a semantic relationship between, elements in which a change to one element (the independent one) may Affe CT The semantics of the other element (the dependent one). Graphically, a dependency is rendered as a dashed line, possibly directed, and occasionally including a label.

The first dependency, which represents the semantic relevance of two model elements, is reflected in the change of one element (the semantically independent one) that affects the semantics of the other element (the one with dependencies). Graphically, a dashed line is used to indicate dependencies, sometimes with directional arrows, and occasionally with labels to identify dependent detail relationships.

Second, an Association is a structural relationship among classes that describes a set of links, a link being a connection among objects tha T is instances of the classes. Aggregation is a special kind of association, representing a structural relationship between a whole and its parts. Graphically, an association are rendered as a solid line, possibly directed, occasionally including a label, and often cont Aining other adornments, such as multiplicity and end names.

The second union relationship, which represents the relationship between the structures of a class, describes a set of connections between objects that are used to connect classes. Aggregation is a special form of a union relationship, which represents the structural relationship between the general and the part. In graphic representation, a solid line is used to represent a union, sometimes with a directional arrow, or with a label. There are often other features, such as multiplicity, terminal name, and so on.

Third, a Generalization is a specialization/generalization relationship in which the specialized element (the child) builds on the specific ation of the generalized element (the parent). The child shares the structure and the behavior of the parent. Graphically, a generalization relationship is rendered as a solid line with a hollow arrowhead pointing to the PARENT.

A third general relationship. Specialized elements (child elements) are built on the specifications of common elements (parent elements), and the relationships between them are called specific or generic relationships. Child elements share the structure and behavior of the parent element. In graphic representation, a general relationship is represented as a solid line with a hollow arrow pointing to a common element.

Fourth, aRealizationis a semantic relationship between classifiers, wherein one classifier specifies a contract that another classifier G Uarantees to carry out. You'll encounter realization relationships in both places:between interfaces and the classes or components that realize th EM, and between use cases and the collaborations that realize them. Graphically, a realization relationship is rendered as a cross between a generalization and a dependency relationship.

The fourth implementation relationship, which is a semantic correlation between classifiers. One classifier defines the description, and a classifier ensures that this definition is implemented. There are two places that can be used to implement relationships: interface definition descriptions, classes or components that implement these interface definitions, and use-case definition descriptions that interactively implement the definitions of use cases. In graphic representation, the implementation relationship is represented as a dashed line with a hollow arrow.

These four elements is the basic relational things the include in a UML model. There is also variations on these four, such as refinement, Trace, include, and extend.

These four elements are the basic relational components that will be used when modeling. Variation relationships from these four elements are: refining, tracing, including and extending.

The Basic Association of UML