What is UML Activity Diagrams
an activity diagram (activity diagram: A special case of a statechart
diagram in which all of the states are action states and the
transitions are triggered by the completion of actions in the source
state.) to describe the internal behavior of a method and represent a
flow driven by internally generated actions.
In Edraw Professional, the UML Activity Diagrams template and shapes are in the Software folder.
Who can use them and how
* Software developers: Represent software applications using the Unified Modeling Language (UML) notation.
* Software developers: Illustrate and interpret software application relationships, actions, and connections.
* Program managers: Show high-level static software structures in presentations and specification documentation.
UML Activity Diagram Symbols
Edraw is ideal software to draw UML activity diagrams Examples of UML Activity Diagrams
How to draw UML activity diagrams
1. Identify the scope of the activity diagram
by identifying what it is you are modeling. Is it a single use case? A
portion of a use case? A business process that includes several use
cases? A single method of a class? Once you identify the scope of your
diagram, you should add a label at the top, using a note, indicating an
appropriate title for the diagram and a unique identifier for it. You
may also want to include the date and even the names of the authors of
2. Add start and end points
activity diagram has a starting point and an ending point, so you might
as well add them right away. In UML Distilled (see Resources), Fowler
and Scott make ending points optional. Sometimes an activity is simply a
dead end but, if this is the case, then there is no harm in indicating
the only transition is to an ending point. This way, when someone else
reads your diagram, he or she knows you have considered how to exit
3. Add activities
you are modeling a use case, introduce an activity for each major step
initiated by an actor (this activity would include the initial step,
plus any steps describing the response of the system to the initial
step). If you are modeling a high-level business process, introduce an
activity for each major process, often a use case or a package of use
cases. Finally, if you are modeling a method, then it is common to have
an activity for this step in the code.
4. Add transitions from the activities
style is always to exit an activity, even if it is simply to an ending
point. Whenever there is more than one transition out of an activity,
you must label each transition appropriately.
5. Add decision points
the logic of what you are modeling calls for a decision to be made.
Perhaps something needs to be inspected or compared to something else.
Important to note is that the use of decision points is optional. For
example, in Figure 1 I could just as easily have modeled the accepted
and rejected transitions straight out of the "Enroll in University"
6. Identify opportunities for parallel activities
activities can occur in parallel when no direct relationship exists
between them and they must both finish before a third activity can. In
Figure 1 you see it is possible to attend the overview or enroll in
seminars in either order, but both activities must occur before you can
end the overall process.