1 SWE Introduction to Software Engineering Lecture 16 – System Modeling An Example

2 Lecture Objectives Object-Oriented Analysis - An example Safe-Home System

3 Object-Oriented Analysis Basic user requirements must be communicated between the customer and the software engineer. Classes must be identified. A class hierarchy is defined. Object-to-object relationship should be represented. Re-apply the above tasks iteratively until the model is complete.

4 Safe-Home surveillance system - Home Owner Access camera surveillance via the internet. Select camera to view. Request thumbnails from all cameras. Control panel and zoom for a specific camera. Selectively record camera output.

5 Use Case: Access camera surveillance Actor - Homeowner Please refer to the handout for the detailed use case description.

6 Use Case: Access camera surveillance The homeowner select ‘pick a camera’. The system displays the floor plan of the house.

7 Use Case: Access camera surveillance Can the actor take some other action at this point? Is it possible that the actor will encounter some error condition at this point? Is it possible that the actor will encounter some other behavior at this point?

8 Activity Diagram UML activity diagram supplements the use case by providing a graphical representation of the flow of interaction within a specific scenario.

9 Swim-lane Diagrams UML swim-lane diagram is a useful variation of the activity diagram Allows the modeler to represent the flow of activities described by use case; and Indicate which actor or analysis class has responsibility for the action described by an activity rectangle.

10 Key points Use Case Diagrams Activity Diagrams Swim-lane Diagrams