In sequence diagrams, you can create lifelines to show how instances
participate in interactions between source elements in applications.
To create a lifeline:
- With a sequence diagram open, in the Palette, click Lifeline.
- Click in an interaction frame where you want to add the new lifeline.
- Type a name for the new lifeline to indicate that the type name
is to be specified, and press Enter.
A lifeline is created at the x-location where you clicked in the interaction
frame, is aligned vertically with other lifelines in the interaction, and
extends downward to cover the length of the interaction frame.