1. Activity Diagrams

2. Definition Activity diagrams represent the dynamics of the system.
They are flow charts that are used to show the workflow of a system.
They show.
The flow of control from activity to activity in the system,
What activities can be done in parallel.
Alternate paths through the flow.
They can show the flow across use cases or within a use case.
Helpful in developing system sequence diagrams (SSD)

3. Activity Diagram
Supplements the use-case by providing a diagrammatic representation of procedural flow
Details:
Start is a single circle
End is a bulls-eye
Decisions are diamonds (guards must be on both branches of the diamond!)
Start Marker
Stop Marker

4. Activity Diagram Example
Fork/Branch
To show concurrent activity, activity diagrams allow branches and joins. You can also reference or include other activity diagrams
Got here Class -- Sept 30th 2008
Synch. Bar (Join)
Join
Splitting Bar (Fork)

5. [no coffee]
[no cola]
Find
Beverage
[found coffee]
Put coffee
in filter
Add water
to reservoir
Get
cups
Get can
of cola
Put filter
in machine
Turn on
machine
Brew
coffee
Pour
coffee
Drink
Beverage

6. When to Use Activity Diagrams
Do use them for
Analysing Use Cases.
Understanding workflow across many Use Cases.
Dealing with multi-threaded applications.
Don’t use them
to see how objects collaborate.
to see how an object behaves over its lifetime.

7. Example: Activity Diagram for Receiving an Order
Receive
order
* for each line
item on order
Check line
item
[failed]
Authorise
Payment
[in stock]
Cancel
Order
[succeeded]
Assign
to Order
[need to reorder]
Reorder
item
[stock assigned
to all line items
and payment
authorised]
Dispatch
Order

8. Example: Activity Diagram for receiving Supply
Receive
Supply
Example: Activity Diagram for receiving Supply
Choose outstanding
order items
* for each chosen order item
Assign goods
to order
[all outstanding order items filled]
Add remainder
to stock
Dispatch
Order

9. Combined Activity Diagram
Receive
order
Receive
Supply
* for each line
item on order
Choose
outstanding
order items
Check line
item
Authorise
Payment
[in stock]
[failed]
* for each chosen order item
[succeeded]
Assign
to Order
Assign goods
to order
Cancel
Order
[need to reorder]
Reorder
item
[stock assigned
to all line items
and payment
authorised]
[all outstanding order items filled]
Dispatch
Order
Add remainder
to stock

10. [all outstanding order items filled]
Finance
Order
Processing
Stock
Manager
Receive
order
Receive
Supply
* for each line
item on order
Choose
outstanding
order items
Check line
item
Authorise
Payment
[in stock]
[failed]
* for each chosen order item
[succeeded]
Assign
to Order
Assign goods
to order
Cancel
Order
[need to reorder]
Reorder
item
[stock assigned
to all line items
and payment
authorised]
[all outstanding order items filled]
Dispatch
Order
Add remainder
to stock
With Swimlanes

11. Example: Business Level Activity Diagram of the Library
With Swimlanes
member
Librarian
[borrower]
Find book on shelf
[returning]
[returner]
Wait in queue
[borrowing]
Record return
Put book back of shelf
Record borrowing
Prepare for next
member