31269 Lecture Notes - Lecture 9: Sequence Diagram
Week 9 Lecture: Interaction Modelling with Sequence Diagrams
Interaction Diagrams
• UML includes interaction diagrams to illustrate how objects interact via
messages.
• They model how a group of objects collaborate to perform some behaviour.
• There are two types of interaction diagrams:
o Sequence Diagram
o Communication Diagram
Sequence Diagram
• A sequence diagram is a graphical/visual representation of a
scenario/narrative of a use case. Typically, it captures the behaviour of one
use case and visualises a use case.
• Objects are identified in the process or use case narrative and represented in
a Lifeline Box.
• It shows communication between the identified objects in terms of messages
that are passed from source to target lifeline over a period of time.
• It also shows a succession of interactions (methods) between classes or
object instances over time in a sequence.
Components
• Sequence diagrams illustrate interactions in which each new object is added
to the right, as above.
• The lifeline boxes across the top are individual participants in a sequence.
• The Activation/Execution bar shows the period of time during which an
operation/method executes and is shown along the lifeline. It indicates the
focus of control and how long the object is active. These are the vertical
columns underneath each lifeline box.
find more resources at oneclass.com
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Document Summary
Week 9 lecture: interaction modelling with sequence diagrams. Interaction diagrams: uml includes interaction diagrams to illustrate how objects interact via messages, they model how a group of objects collaborate to perform some behaviour, there are two types of interaction diagrams, sequence diagram, communication diagram. Sequence diagram: a sequence diagram is a graphical/visual representation of a scenario/narrative of a use case. Typically, it captures the behaviour of one use case and visualises a use case: objects are identified in the process or use case narrative and represented in a (cid:862)lifeline box(cid:863). It shows communication between the identified objects in terms of messages that are passed from source to target lifeline over a period of time. It also shows a succession of interactions (methods) between classes or object instances over time in a sequence. It indicates the focus of control and how long the object is active.
