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SWE 205 - Introduction to Software Engineering

Lecture 16 – System Modeling

An Example

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Lecture Objectives Object-Oriented Analysis - An example

Safe-Home System

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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.

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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.

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Use Case: Access camera surveillance Actor - Homeowner Please refer to the handout for the

detailed use case description.

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

the house.

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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?

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Activity Diagram UML activity diagram supplements the

use case by providing a graphical representation of the flow of interaction within a specific scenario.

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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.

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Key points Use Case Diagrams Activity Diagrams

Swim-lane Diagrams