15_Communication_Diagrams

1 .Lecture 15 – Communication Diagrams Describe the difference between a sequence diagram and communication diagram Given a use-case scenario, sketch out an object interaction diagram Given a systems problem description, sketch out a system overview diagram Learning Goals © Paul Davies, C. Antonio Sanchez. Not to be copied, used, or revised without explicit written permission from the copyright owner.

2 .Object Diagram Like a class diagram, but shows instances of classes (i.e. objects). Underline the name : class type to show it is an instance, shows any known values within the instance. Communication Diagram 2 Class Diagram Object Diagram Source: Fowler, Martin.  UML distilled: a brief guide to the standard object modeling language . Addison-Wesley Professional, 2004.

3 .Communication Diagram Similar to the object diagram, pictoral version of a sequence diagram. Numbered messages go on the interaction arrows. Communication Diagram 3

4 .Object Interaction Diagram Not official UML!!  Anything goes!!! Communication Diagram 4 Usually similar to a communication diagram, with messages removed. Use anything you like that helps make it clear what’s going on. Chef 1 Server 1 Server 2 Customer 1 Chef 2 Chef 3 Customer 2 Customer 3 ... ... Order Queue Serve Queue

5 .Communication Diagram 5 Elevator Control System Gas Station Simulation Gas Station

6 .Communication Diagram 6 Amazoom Automated Warehouse

7 .Object Interaction Diagram Provide an overview of the interaction, give a strong-enough indication of what needs to communicate with what. Communication Diagram 7 Can be used to document each use-case, or use-case scenario. Can also be used to provide a high-level overview of the system components. If the diagram shows the overall system design, we sometimes call it a System Overview Diagram .

8 .UML Summary Use-Case Diagram: shows all use-cases, initiated by actors Class Diagram: structure of class hierarchies, associations between classes Sequence Diagram: documents sequence/timings of events for each use-case scenario Communication Diagram: pictoral version of sequence diagram, can be used to replace a sequence diagram in a given use-case scenario Non UML Object Interaction Diagram: communication diagram without messages, plus extras to improve clarity of interactions System Overview Diagram: high-level interaction of major system components Communication Diagram 8