Constructing the Library Analysis Model - Adding a Class Diagram

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1 - Adding a Class Diagram Prerequisite On completion of the requirements model, your project explorer window should look something like below. You model should contain a number of public and administrative uses cases with at least one activity diagram showing the a main library workflow (business model). Two typical use case diagram from the requirements model are:

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3 Comment on Analysis Model This is where we construct our class diagrams and sequence diagrams. The class diagrams at the analysis level give us a high level view of the significant classes in the system. These classes correspond to entities in the business domain. A sequence diagram help us visualise and or analyse how instances of these classes (objects) interact to realise a use case. They help us to begin to visualise how the eventual software objects may interact. The construction of more detailed class diagrams which form a blueprint for the eventual implementation are deferred to the design stage. Constructing the Analysis Model In the Project Explorer window, right click on the models folder and select Create UML Model, make sure standard template is selected and click on next. On the next input window as shown below, select the Analysis and Design category and the Blank Analysis Package template, name the model "Analysis Model". 3

4 Important step: Click Next twice and when the following window appears, make sure UML Element Building Blocks and UML Diagram Building Blocks are fully selected as shown. Then click Finish. Should get a screen like: 4

5 Adding Classes to the Model Right click on the Analysis Model folder in Project Explorer and add two UML packages, one for each of the two business areas (Admin and Public). Double click on Main class diagram in Analysis Model folder in project explorer in order to activate it. A class palette should be visible on the right hand window of RSA and the a blank diagram should be available for drawing on. Use the class icon from the palette to drop a class onto the diagram and name it Book. Add another class called Copy in the same manner. Right click on Analysis Model in project explorer, select Add UML / Class, name the new class Member to get: The class Member is in the analysis model but not on the diagram, so use the mouse to drag it onto the diagram from the Project Explorer window. Next we want to draw associations between the classes that show the multiplicities without showing the role names. To do this select Window / Preferences / Modelling / UML Diagrams / Class and make certain that Show multiplicity is enabled while Show roles is disabled as shown. Note this Preferences window is quite useful, e.g. when drawing use cases you could have used this mechanism to prevent multiplicities and role names been shown on the links between the actors and use cases instead of deleting them from the diagram. 5

6 Using either the Association icon from the class palette or the output pins on the class diagram, draw the class associations show below. Activate the properties window for each association one at a time by left-clicking on it in the class diagram. The set the multiplicities on both ends of each association to the correct value. Should get: 6

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8 Adding Attributes to Classes Right click on Member class on class diagram and select Add UML / Attribute. Call the attribute name as show. Similarly add address and tel attributes to Member class. Now we will use another way to add an attribute. In the Project Explorer window right click on the class icon for Copy in and select Add UML / Attribute, name it status. Now we will try a third way to add a class attribute. Select the Book class either in the Project Explorer window or from the class diagram. You should notice a Properties window for the class appear at the bottom of RSA. Select the attributes tab On the top right hand corner of the attributes property window you should see the icon. Click on the arrow part to insert a new attribute and call it qty. Will have 8

9 We now want to show that qty (quantity) has an integer type. So under the Type property of the attribute qty, click on the 3 dots in the icon. You should get the popup window Type in int (for integer) and select the UML primitive type integer as shown. 9

10 The type for qty should be visible in the class diagram as show below. If not right click on Member class, select Filters / Show signature. We will now show that Copy status is of type String. In the Project Explorer window, select the status attribute of the Copy class. Will see: 10

11 In the Properties window of status, click on the Select type button and type in string. Select UML primitive type String as shown. Should now have 11

12 Now add more attributes that you think appropriate and also give them types. Finally add a new class Staff and make it a specialisation of Member. The link between them will not be an association but a generalisation. 12