OO Design Requirement specification the first steps of design To represent a system design First, to identify and represent classes and objects Second to identify the interactions and relationships among objects and classes associations · Compositions Aggregations Inheritance To provide the details in program design Insert computational features in the models Insert some class library details Consider nonfunctional requirements
OO Design • Requirement specification, the first steps of design. • To represent a system design – First, to identify and represent classes and objects. – Second, to identify the interactions and relationships among objects and classes. • Associations • Compositions • Aggregations • Inheritance • To provide the details in program design. – Insert computational features in the models – Insert some class library details – Consider nonfunctional requirements
Use cases(用例) Describe particular functionality to exhibit how a user, external system, and other entity dialog with the system Scenario场景 Script脚本
Use Cases (用例） • Describe particular functionality to exhibit how a user, external system, and other entity dialog with the system. • Scenario 场景 • Script 脚本
Use case diagrams(用例图) Actor(角色) a entity interacting with the system Or a role that an entity plays with respect of the system User · Device · Another systen Cases(用例) a depiction of some aspect of functionality Extensions To extend a use case to illustrate a different or deeper perspective Uses Actually a reuse of an already-defined use case
Use case diagrams（用例图） • Actor（角色） – A entity interacting with the system – Or a role that an entity plays with respect of the system • User • Device • Another system • Cases（用例） – A depiction of some aspect of functionality • Extensions – To extend a use case to illustrate a different or deeper perspective. • Uses – Actually a reuse of an already-defined use case
Overview of royal service station a actor Stand for a case Billing Services Customer Refueling g Parking)Maintenance
Overview of royal service station Billing Services Refueling Parking Maintenance Customer Stand for a case A actor
First extension to include preventive maintenance Pa arkin Refueling Customer Ma anager Maintenance extends Preventive Maintenanc
First extension to include preventive maintenance Preventive Maintenance Maintenance Parking Refueling Customer Manager extends