COMP 310/510 Fall 2013	Lab09: ChatApp Design

In today's lab, we will be working in small groups to work out use cases and  design the interfaces and protocols for the ChatApp project.

The Design Process:

1. Define what the application is supposed to do, e.g. feature list.
2. Write use cases for the features -- the more detailed the better!
3. Organize the use cases into maximally decoupled groups,
   •  The groups form the main sub-systems in the application.
4.  Create the System Block Diagram from those sub-systems
   • Clearly define the roles and responsibilities of each sub-system.
   • Define the API's (Application Programming Interfaces) that the use cases are using to access the use cases in another sub-system 
5. Repeat the process to design the interiors of the sub-systems.
6. Code the sub-systems.

Note that coding is the LAST thing that is done!

Use cases can be created using (non-exhaustive list):

• Microsoft Visio
• http://creately.com/  -- On-line diagramming tool (sign up for free account).

For reference:

• Lec29:  Use case and ChatApp design guides
• Java Resources page on Use Cases
• HW08: ChatApp required specifications

© 2013 by Stephen Wong