Activity and Class Diagrams for Modelling Business Process

1
Activity and Class Diagrams for Modelling
Business Process

• Richard Hopkins
• rph_at_nesc.ac.uk
• UML for Use Cases
• NeSC, Edinburgh, Jan 5/6 2006

2
Development Process
Partially articulated requirements
to elucidate requirements what entities exist
and how each behaves
Capture Requirements
Use Case Diag.
Requirements
Construct Model of Overall system
Class Diag.
Structure

Behaviour
3
More Technical Diagrams

• Activity Diagram
• Flowchart
• Deals with the whole behaviour of one actor
• Class Diagram
• shows the structure of the types of entities
  involved in the system
• These are more complex diagrams
• Usually used for the Software design internal
  operation
• Can be used to describe external operation
• Might be useful in clarifing requirements

4
Activity Diagram (flowchart)
Swimlanes separate Actors persons or systems
user
librarian
Find Book on shelf
borrower
returner
returning
borrowing
Synchronisation bar Start/Collect concurrent
activities concurrent non-sequenced Any order
or parallel
decision
activity
guard
transition
Start / stop
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Class Diagram
User
Item
Student
Staff Member
Journal
Copy
Article
Book

• each box represents a class of entities
• here real world entities
• Generalisation ( Inheritance)
• Every StaffMember is a User
• Every Student is a User
• If User can do it, so can Student and StaffMember
• Every Book is an item Every Journal is an item
• Doing something to an item means doing that to a
  book or to a Journal
• To facilitate understanding of / communicate
  about
• The application domain
• NOT the structure of system implementing it

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Class Associations
User
Item
Is part of
contains
has out
Is copy of
Student
Staff Member
Journal
Copy
Article
Book
has out
Ordered print-off

• Associations knows about
• there is an association line if there is a
  relevant real-world association
• any user can have out a copy (of a book)
• a Staff Member can have out a Journal
• an article can be part of a Journal
• .
• only label one end

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Multiplicities
Number of Copy objects that can be associated
with one student object At least 0 At most 6
0..1
Student
0..6
1
1..
Exactly 1
Copy
Book
has out
Is copy of
0..12
Staff
0..1
0 or 1
At least 1,no upper limit

• Constrains the number of entities at one end that
  can be associated with one entity of the other
  end (in this association type, at any one time)
• Either single number (usually 0 or 1)
• Or range X .. Y.
• for Y means no upper limit

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Questions?
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Practical Business Process Model

• Working in groups
• For the system of your Use Cases
• or some other groups
• E F seem to me to show relatively little
  potential for entity structuring
• Construct a Class diagram of the entities
  involved
• Construct an activity diagram for (part of) the
  behaviour of one entity class
• How easy? How useful
• Use pencil paper or VP-UML
• 2 hours (ish)