Software Engineering
Activity Diagram
,Activity Diagram
• Activity is a particular operation of the system.
• Activity diagram is basically a flowchart to
represent the flow from one activity to another
activity. The activity can be described as an
operation of the system.
,Activity Diagram(Cont.)
• Itdoes not show any message flow from one
activity to another. Although the diagrams look
like a flowchart, they are not.
• Thepurpose of an activity diagram can be
described as −
• Draw the activity flow of a system.
• Describe the sequence from one activity to another.
• Describe the parallel, branched and concurrent flow of
the system.
, Activity Diagram V.s Use Case
(Cont.)
• An activity diagram is used to model the workflow depicting conditions, constraints,
sequential and concurrent activities.
• On the other hand, the purpose of a Use Case is to just depict the functionality i.e.
what t he system does and not how it is done.
• So in simple terms, an activity diagram shows ‘How’ while a Use case shows ‘What’
for a particular system.
• The levels of abstraction also vary for both of them. An activity diagram can be used
to illustrate a business process (high level implementation) to a stand alone
algorithm (ground level implementation).
• However, Use cases have a low level of abstraction. They are used to show a high
level of implementation only.
Activity Diagram
,Activity Diagram
• Activity is a particular operation of the system.
• Activity diagram is basically a flowchart to
represent the flow from one activity to another
activity. The activity can be described as an
operation of the system.
,Activity Diagram(Cont.)
• Itdoes not show any message flow from one
activity to another. Although the diagrams look
like a flowchart, they are not.
• Thepurpose of an activity diagram can be
described as −
• Draw the activity flow of a system.
• Describe the sequence from one activity to another.
• Describe the parallel, branched and concurrent flow of
the system.
, Activity Diagram V.s Use Case
(Cont.)
• An activity diagram is used to model the workflow depicting conditions, constraints,
sequential and concurrent activities.
• On the other hand, the purpose of a Use Case is to just depict the functionality i.e.
what t he system does and not how it is done.
• So in simple terms, an activity diagram shows ‘How’ while a Use case shows ‘What’
for a particular system.
• The levels of abstraction also vary for both of them. An activity diagram can be used
to illustrate a business process (high level implementation) to a stand alone
algorithm (ground level implementation).
• However, Use cases have a low level of abstraction. They are used to show a high
level of implementation only.
