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OCUP 2 Foundation study materials
OCUP 2 Foundation study resources

OCUP 2 Foundation: UML Structural Diagram Types

OCUP 2 Foundation · Work through your exam, one topic at a time.

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UML Structural Diagram Types

What the exam tests

Structural diagrams in UML 2.5 are seven: Class, Object, Package, Component, Composite Structure, Deployment, and Profile. Foundation questions check the classifier each diagram is built from, its notation, and which relationships are legal.

Core rules

  • Class diagram: classifiers (Class, Interface, DataType, Enumeration), features (Properties and Operations), and relationships: association, generalization, realization, dependency, aggregation, composition, association class.
  • Object diagram: instances written name : Type or : Type, with links instead of associations; a snapshot at one point in time.
  • Package diagram: packages with «import» or «access» dependencies, and merge.
  • Component diagram: components with provided and required interfaces (ball-and-socket or «interface»), ports, connectors, «manifest».
  • Composite structure: internal parts, ports and connectors; a part is typed by a classifier.
  • Deployment: nodes drawn as 3-D boxes, artifacts, «deploy» dependencies, communication paths.
  • Profile: «profile», «stereotype», «metaclass»; stereotypes extend metaclasses.

Worked example

An order model has Order with a filled diamond to OrderLine at multiplicity 0..*. Reading: each OrderLine is owned by exactly one Order, and deleting the Order deletes its lines. If the diamond were hollow (shared aggregation), the parts could exist independently and be shared. A separate association Order to Customer with a navigable arrow shows Order can reach Customer; role names and multiplicities refine it.

Traps

  • Hollow versus filled diamond: shared aggregation does not imply ownership or deletion.
  • Generalization is a solid line with a hollow triangle; realization is dashed with a hollow triangle.
  • Drawing a reference as an attribute when it is an association end: both are Properties in the metamodel, but notation differs.
  • Deployment nodes are physical targets; components are logical units.
  • A profile is a package with «profile» that applies stereotypes; it is not an ordinary model library.