In sequence diagrams, you can create lifelines to represent objects in a system.
Procedure
- Drag a Sequence diagram shape to the whiteboard from the UML palette.
- Drag a Lifeline shape to the sequence diagram container element.
The
Edit Lifeline window is displayed.
Note: The size of the lifeline
element gets automatically adjusted to the length of the sequence diagram element. Likewise, when
the sequence diagram element size is increased or decreased, the size of the lifeline elements are
adjusted too to fit the new size. When the size of the sequence diagram is reduced, you are not
allowed to reduce after a certain limit, based on the size of the existing lifelines it contains, to
avoid losing any existing messages or spillover of messages beyond the boundary of the
diagram.
- Type the name of the lifeline.
You can either provide a new name or search for an existing lifeline name and select an existing
element type with its attributes.
- Click OK. A lifeline is created.
When you select a lifeline, you see that each lifeline has multiple
magnet points vertically, which can be used to connect to another lifeline within the sequence
diagram.
Results
When you create a lifeline in a sequence diagram, the lifeline is aligned vertically with
other lifelines in the interaction, and extends downward.