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Information Systems Engineering
Activity Diagram
Source Mastering UML with Rational Rose 2002
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Activity DiagramActivity diagrams illustrate the flow of functionality in a system
It used in requirements gathering to illustrate the flow of events through a use case
These diagrams define where the workflow starts, where it ends, what activities occur during the workflow, and in what order the activities occur
An activity is a task that is performed during the workflowSource Mastering UML with Rational Rose 2002
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Elements of Activity DiagramNotation RepresentationShow where the flow begins. Each activity diagram must have one and only one start state
Element
Start State
End State
Show where the flow ends. You can have more than one end state on the diagram (Optional)
Activity
A step in the process
Select Flight
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Elements of Activity Diagram cont.Notation RepresentationAn entity that is used or changed by an activity in the flow. You can understand where and how the object's state changes.
ElementObject Name [State]
Objects
Object Flows
Link objects to activities. from an activity to the object it changes, or from the object to the activity that needs to use it (as input).
Transitions
shows how the flow of control moves from one activity to another
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Elements of Activity DiagramNotation RepresentationA way to show that two or more branches of a flow occur in parallel. It can be either horizontal or vertical
cont.
Element
Synchronization
Decision points
Shows decision point in the work flow
Source Mastering UML with Rational Rose 2002
Ticket Enter Credit Information [Invalid account, credit system not available ] [Unconfirmed]
[Approved]
Reserve Seat
Ticket [Purchased]
Generate Confirmation Number
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Elements of Activity Diagram
Activity: ActionsA detailed steps can be added to the activity by using actions. Actions are smaller steps that take place within an activity They may occur at one of four times:
Upon entering the activity. An entry action occurs as soon as the activity begins - "entry When exiting the activity. An exit action occurs as you are leaving the activity - "exit While performing the activity. These actions occur while in the activity and continue until you leave the activity - do Upon a specific event. These actions happen if and only if a specific event occurs - "event followed by the event nameSource Mastering UML with Rational Rose 2002
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Elements of Activity Diagram
Activity: Actions
cont.
Display Available Flights entry/ Find all flights for selected cities entry/ Determine flights with available seats do/ Display list of flights with available seats event/ User request cost information/ Display cost information
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Elements of Activity Diagram
Transitions: Limitations
Event:
The event must happen in order for the transition to occur The transition arrow is labeled with the event name, along with any arguments in parenthesis
Reserve seat
Cancel
Refund credit purchase
Cancel reservation
Source Source Mastering UML with Rational Rose 2002
Mastering UML with
Elements of Activity Diagram
Transitions: Limitations
cont.
Guard condition:
While an event triggers a transition, a guard condition controls whether or not the transition can occur If a guard condition is present, it must be true in order for the transition to occur The guard condition is listed along the transition arrow, following any event, and is enclosed in square bracketsReserve seat
[New reservation]Mastering UML with
Generate Confirmation Number
Source Source Mastering UML with Rational Rose 2002
Elements of Activity Diagram
Synchronization & Decision Point ExampleEnter Credit Information [Invalid account, credit system not available ]
[Approved]
Reserve seat
Generate Confirmation Number
Generate E-mail
Display Confirmation Number SourceMastering UML with Rational Rose 2002
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ExampleDraw a detailed activity diagram for the rent a video item use case.1. 2. 3. 4. 5. 6.
Clerk scans card Clerk scans desired video(s) Terminal displays details of each video scanned Verify customer(not a customer, unreliable, customer found) Terminal displays price and due date Terminal prints receipt for signature
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Example
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PracticeDraw a use case diagram for a Bank system The following use cases are defined: Open customer account Deposit funds Transfer funds Withdraw money Order bank statment View account history Change PIN
Draw a detailed activity diagram for the Open customer account and Withdraw money use cases.
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Use case Diagram:
Bank system
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Activity Diagram:
Open customer account
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Activity Diagram:
Withdraw money
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