1 BTS330 Visual Modeling

What is Visual Modeling? 2 Copyright © 1997 by Rational Software Corporation Computer System Business Process Order Item Ship via “ Modeling captures essential parts of the system.” Dr. James Rumbaugh Visual Modeling is modeling using standard graphical notations

Visual Modeling Captures Business Process 3 Copyright © 1997 by Rational Software Corporation Use Case Analysis is a technique to capture business process from user’s perspective

Visual Modeling Manages Complexity 4 Copyright © 1997 by Rational Software Corporation Use visual modeling to analyze and design your application

What is UML? UML stands for Unified Modeling Language UML is the standard language for visualizing, specifying, constructing, and documenting the artifacts of a software- intensive system Can be used with all processes, throughout the development life cycle, and across different implementation technologies 5 Copyright © 1997 by Rational Software Corporation

UML Supports Application Development 6 Copyright © 1997 by Rational Software Corporation Classes application partitioning Business Objects Relationships Business Process Objects Use Cases large scale system Scenarios Components Microsoft ActiveX/COM Microsoft ORDBMS Oracle CORBA OMG

UML Concepts UML may be used to: Display the boundary of a system & its major functions using use cases and actors It is intuitive to interpret 7 Copyright © 1997 by Rational Software Corporation

UML Concepts UML may be used to: Illustrate use case realizations with interaction diagrams 8 Copyright © 1997 by Rational Software Corporation

UML Concepts UML may be used to: Represent a static structure of a system using class diagrams 9 Copyright © 1997 by Rational Software Corporation Payment amount Sale date time Pays-for. 1 1

UML Concepts UML may be used to: Model the behavior of objects with state transition diagrams 10 Copyright © 1997 by Rational Software Corporation

UML Concepts UML may be used to: Reveal the physical implementation architecture with component & deployment diagrams 11 Copyright © 1997 by Rational Software Corporation

UML Concepts UML may be used to: Extend your functionality with stereotypes 12 Copyright © 1997 by Rational Software Corporation

Rational’s Rose Rational Software History Rational Software IBM Rational RoseRational Rose 13

Requirements Gathering Need to find out what the user requires in the system (user’s needs) Allows the Analyst to clearly understand the user’s requirements Need to describe the interaction between users of the system and the system itself Describes what the system is to do, not how it is going to do it (features)

Requirements Gathering Done: Identifying stakeholders Business areas Next Steps: Systems Use Case Diagrams Systems Use Case Descriptions

Systems Use Case Diagrams and Descriptions Based on the dialog metaphor

Documenting Dialogs Many methods exist for documenting Dialogs Systems Use Case diagrams: the dialog between the actor and the system Written descriptions such as systems use case descriptions or scenarios Sketches of screens, i.e. storyboards

Actors “Can represent humans or other systems Define the roles that users or other systems play when interacting with the system Are outside the system, and usually outside the control of the system Impose requirements on what the system being built must do”* * Use Case Modeling, Kurt Bittner & Ian Spence, Addison-Wesley, 2003, p. 22

Actors User Somebody who maintains the data, uses the data or generates reports Applications External processes or software systems ( interface) Devices External sensors (printers, scanners) Time Events System clock

UML Notation “I can be a person, a department, a system, hardware, scheduler, and so on”. “I am an actor. I play a role that involves using the system. I am outside of the system.” “My name indicates my role.” Order Clerk Actors are represented in UML by a ‘stick’ person

Systems Use Case “Each use case delivers something of value to at least one of the actors. The concepts of actor goals and the delivery of value to the actors are fundamental to the successful discovery, definition, and application of use cases.”* *Use Case Modeling, Kurt Bittner & Ian Spence, Addison-Wesley, 2003, p.

Systems Use Case “The use case should reflect the goals of the actors and enable, at least in part, their achievement”* * Use Case Modeling, Kurt Bittner & Ian Spence, Addison Wesley, 2003, p. 23

UML Notation “Visual representation of the dialog between the actor and the system The ellipse is a graphical representation of a use case It is a placeholder for a description of how the system and its actors interact”* *Use Case Modeling, Kurt Bittner & Ian Spence, Addison-Wesley, 2003, p. 23

Systems Use Case Diagram “Visual representation of the dialog between the actor and the system (each use case) The system and its actors interact by sending signals or messages to one another”* *Use Case Modeling, Kurt Bittner & Ian Spence, Addison-Wesley, 2003, p. 25

Systems Use Case Diagram  “To indicate such interactions, we use a communicate association between the use case where the interaction occurs and the actors involved in the interaction”. * * Use Case Modeling, Kurt Bittner & Ian Spence, Addison-Wesley, 2003, p. 25

System Use Case Diagram “The communicate association represents a dialog between the actor and the system, a kind of communication channel over which data flows in both directions during the dialog.”* *Use Case Modeling, Kurt Bittner & Ian Spence, Addison-Wesley, 2003, p. 26

Systems Use Case Diagram “A use case has at most one communicate association to a specific actor, and an actor has…one communicate association to a specific use case, no matter how many interactions there are”* *Use Case Modeling, Kurt Bittner & Ian Spence, Addison-Wesley, 2003, p. 25

System Use Case Diagram System Boundary Communication Actor

Systems Use Case Diagram “The complete network of such associations provides a static picture of the communication between the system and its environment.”* (the boundaries of the system) *Use Case Modeling, Kurt Bittner & Ian Spence, Addison-Wesley, 2003, pp

30 Use Case Diagram Shows the functionality that the system will provide and which users (actors) will communicate with the system Done using Rational Rose Documents the scope of the system under development

31 Use Case Diagram Actors are represented by a ‘stick’ figure Use Cases are represented by an oval

32 Use Case Diagram Sample Use Case Diagram

33 Modeling Use Cases Inventory Systems Use Case Diagram

34 Closing Note Do not confuse use cases with functions i.e. invalid use cases: Add Order Update Order Delete Order

35 Use Cases How many use cases should a project have? As many as are needed to address the functionality of the system

Systems Use Case Diagram Package the use case model Makes model more manageable Used to: Manage complexity Reflect functional areas (i.e. business areas)