SYS466: Analysis and Design Using OO Models Lecture 8 Domain Classes – More on Relationships

Where are we going? Analyze Requirements as per Use Case Model Analyze Requirements as per Use Case Model System Sequence Diagrams System Sequence Diagrams Domain Model (Conceptual Class Diagram) Domain Model (Conceptual Class Diagram) Interaction (Sequence) Diagrams Interaction (Sequence) Diagrams Design Class Diagram Design Class Diagram

Requirements Gathering (Specification) Use Case Analysis Interaction Modeling Coding 1. Refine Use Case Description – Scenarios 2. Model system input and output events (Systems Sequence Diagram - SSD) 3. Noun filtering - Domain Class Diagram (conceptual classes) - Identify attributes of conceptual classes - Identify relationships between conceptual classes (association and composition) 1. Model object interaction & definition of operations using Sequence Diagrams 2. Refine the Domain Class Diagram – show final relationships (associations, composition, inheritance) Testing SYS366 SYS466 PRJ Business and System Use Case Diagrams 2. Business and System Use Case Descriptions ** PRJ566 – encompasses SYS366, SYS466, DBS201 and DBS301

Relationships Multiplicity of relationships can be 1:1, 1:M, M:N Multiplicity of relationships can be 1:1, 1:M, M:N M:N relationships can exist in a class diagram M:N relationships can exist in a class diagram

Sample Scenario HD Rent Video using cash ActorSystem Click on rent video button on the menuDisplay rent a video page with a prompt for customer id. Enter customer idRetrieve customer information (id, name, phone number) and diplays rent a video page showing cust id, name, phone number and a prompt for video id Enter video idRetrieve video id, desc, rental price and display the video page showing id, desc, rental price and update and display subtotal Click on done buttonRetrieve and display payment methods in a drop down list on the rent a video page Select cashPrompt for amount paid Enter amount paidCalculate change, update stock, display change and due date on the rent a video page, and print a receipt Click exitDisplays menu and end the scenario

Sample Scenario Noun or Noun PhraseClass or attribute? Name of potential conceptual class or attribute If attribute, what class does it belong to? Customer IDAcustIDCustomer Customer informationCCustomer NameAnameCustomer Phone numberAphoneNumberCustomer Video idAvideoIDVideo DescAdescriptionVideo Rental priceArentalPriceVideo Payment methodsAmethodTypePaymentMethod Amount paidAamountPaidRental Transaction ChangeAchangeRental Transaction StockAquantityOnHandVideo Due dateARental Transaction receiptCReceipt

Sample Scenario The above noun filter would result in this class diagram: The above noun filter would result in this class diagram: Note the M:N relationship!

Sample Scenario When an M:N relationship exists, an intersection or association class could be created – under certain circumstances When an M:N relationship exists, an intersection or association class could be created – under certain circumstances

Classes When to create the intersection or association class? When to create the intersection or association class? If an attribute exists that should be associated with it, then create it at the time the noun filtering is done If an attribute exists that should be associated with it, then create it at the time the noun filtering is done Otherwise, show the M:N relationship in the class diagram Otherwise, show the M:N relationship in the class diagram