Transcript Communication diagrams - School of Engineering and Information
ZEIT2301 Design of Information Systems Interaction Design: Communication Diagrams School of Engineering and Information Technology UNSW@ADFA Dr Kathryn Merrick
Topic 07: Interaction Design Objectives To understand the notation, rules and style guidelines for creating communication diagrams (previously known as collaboration diagrams) To understand one technique for identifying potential interactions between objects is a
CRUD analysis
.
Reference: Text Ch 7 2
Communication Diagrams
Communication diagram
– is a behavioural diagram that shows message passing relationships between objects & actors. It is equivalent to a sequence diagram, but Communication diagram - emphasizes the flow of messages through a set of objects, Sequence diagram – emphasizes the time ordering of messages The analyst/designer may choose either or both.
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Communication Diagrams
Elements of a communication diagram:
Actors
&
objects
Associations
&
messages
– messages are labels on associations Sequence – messages are assigned a sequence number Conditions - messages can be conditional Session 2, 2010 4
Communication Diagram Syntax Session 2, 2010 5
Communication Diagram
Session 2, 2010 6
Communication Diagram - Rent Movie
:
Rented Items 7 print invoice() 1 find_customer() 3 enter_movie() 5 rent(movie) 6 add(customer, movies) 8 generateRentalTotal() 2 search(CustId)
:
Check-out Manager
:
Employee
:
Customer 4 searchBarcode()
:
Inventory Message Object 7
CRUD: an analysis technique
One technique for identifying potential interactions between objects is a
CRUD analysis
.
CRUD
stands
C
: create
R
: read (or reference)
U
: update
D
: delete Use a CRUD matrix … 8
Sample CRUD Matrix
An object of the receptionist class needs to be able to Create, Read, Update and Delete objects of the Patient class.
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Summary
Behavioural Modelling State Machine diagrams
– shows the different states that an object of a single class passes through during its life in response to events.
Can also be used at a higher level to explore the complex behaviour of a system or component, particularly real-time systems.
Interaction Diagrams Sequence diagram
the messages that pass between them. Emphasis on the time ordering of messages sent.
– illustrates the objects that participate in a use case and
Communication diagram
– equivalent to sequence diagrams (i.e. objects & messages), but emphasis on the flow of control between objects.
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