Analyzing the Application

Use case analysis is the standard technique for analyzing the requirements of an application. A use case diagram shows the interaction between the system and actors. An actor is a role that human and/or nonhuman users of the system play when interacting with use cases. Figure 21.2 shows a high-level use case diagram of the university registration system.

The use case diagram in this case consists of actors, such as student, administrator, and order verification system. The following describes the use cases:

• New students register with the system.
  
  
• Existing students log on to the system and can browse the course catalog.
  
  
• A student can select courses and add them to the enrollment cart.
  
  
• A student places an order for the enrollment cart contents.
  
  
• The system verifies the order in the background.
  
  
• An administrator can view the verified orders that need approval for enrollment.
  
  
• An administrator approves the order and enrolls the student in the courses.
  
  
• The system notifies the student of enrollment via e-mail.