Page 96 - DCAP308_OBJECT_ORIENTED_ANALYSIS_AND_DESIGN

Object Oriented Analysis and Design

Notes of the operations. Therefore activity diagram is a special kind of Statechart diagram, but showing
the flow from activity to activity (not from state to state).
Activity – an ongoing non-atomic execution within a state machine. Activities ultimately result
in some action. It’s a real world process or execution of a software routine.
Action – made up of executable atomic computations that result in a change in state of the
system or the return of a value (i.e., calling another operation, sending a signal, creating or
destroying an object, or some pure computation).
Activity diagrams commonly contain:

Activity states and action states
Transitions
Objects
Action states - executable, atomic computations (states of the system, each representing the
execution of an action) – cannot be decomposed.
Activity states – non-atomic; can be further decomposed; can be represented by other activity
diagrams – a composite whose flow of control is made up of other activity states and action
states
An activity diagram illustrates the dynamic nature of a system by modeling the flow of control
from activity to activity. An activity represents an operation on some class in the system that
results in a change in the state of the system.

Did u know? Typically, activity diagrams are used to model workflow or business processes
and internal operation.
Because an activity diagram is a special kind of statechart diagram, it uses some of the same
modeling conventions.
Figure 7.16: Activity Diagram

7.3.1 Basic Activity Diagram Symbols and Notations

Action states: Action states represent the non-interruptible actions of objects. You can draw an
action state in SmartDraw using a rectangle with rounded corners.

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