1. Object-oriented modeling Modeling the functions and dynamics of the system Use case diagram
Karolina Muszyńska
Based on:
G. Schneider , J.P. Winters „Stosowanie przypadków użycia”
S. Wrycza, B. Marcinkowski, K. Wyrzykowski „Język UML 2.0 w modelowaniu SI”

2. Object Modeling Why Object Modeling? Genesis of UML UML diagrams
Use Case Diagrams
From business tasks to Use Cases
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3. Object Modeling
Object modeling is a technique for identifying objects within the systems environment and the relationships between those objects.
Object-oriented analysis (OOA) techniques are used to (1) study existing objects to see if they can be reused or adapted for new uses, and (2) define new or modified objects that will be combined with existing objects into a useful business computing application.
The Unified Modeling Language (UML) is a set of modeling conventions (notations) to specify or describe a software system in terms of objects.
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4. Object Modeling Benefits:
Break a complex system into manageable components
Create reusable components can be plugged into other systems or use them as starting points for other projects
“Object-think” is more realistic !!!
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5. Genesis of UML
Methodological storm in object-oriented solutions ( )
over 50 various object-oriented methods/solutions
Unified Modeling Language (UML)
Third generation OO method
An attempt to combine advantages of previous methods
Basis for the UML standard
Object Modeling Technique (J. Rumbaugh) – UML diagrams notation, analysis and design
Object Oriented Analysis and Design (G. Booch) – analysis and design
Object Oriented Software Engineering (I. Jacobson) – business modeling, use cases
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6. UML Diagrams
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7. UML Diagrams
Structure diagrams.  A type of diagram that depicts the elements of a specification that are irrespective of time.  This includes class, object, package, composite structure diagrams and implementation diagrams: component and deployment diagrams.
Behavior diagrams.  A type of diagram that depicts behavioral features of a system or business process.  This includes activity, state machine, and use case diagrams as well as the four interaction diagrams.
Interaction diagrams.  A subset of behavior diagrams which emphasize object interactions.  This includes sequence, communication, interaction overview, and timing diagrams.
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8. Most common UML Diagrams
Modeling the functions of the system (with a use case diagram).
Modeling the objects within the scope of the system and their relationships (with class and object diagrams for each use case, and then for the integrated system).
Modeling the interactions between objects to complete a function/use case (with a sequence diagram and activity diagram for each use case).
Modeling the behavior / logic of the objects (with a statechart diagram for each complex class).

9. UML Diagrams STATECHART DIAGRAM FOR OBJECT “Order” USE CASE DIAGRAM
Enter New Customer
Create New Order
:customer
:order
Create Order
SHIP ORDER
CREATE ORDER
ORDER
CUSTOMER
SHIPMENT
USE CASE DIAGRAM
CLASS DIAGRAM FOR USE CASE “Create New Order”
SEQUENCE DIAGRAM FOR USE CASE “Create New Order”
Order Clerk
:shipment
Create Shipment

10. Use Case Modeling
Use case modeling is the process of modeling a system’s functions in terms of business events, who initiated the events, and how the system responds to the events.
A use case is a complete sequence of related actions (a scenario), both automated and manual, for the purpose of completing a business function: What the system must do.
An actor represents an external entity that needs to interact with the system to exchange information. An actor is a user, a role, which could be an external system as well as a person.
A temporal event is a system event that is triggered by time. (The actor of a temporal event use case is time.)

11. USE CASE DIAGRAM
Use Case Diagram is a functional description (use cases, actors) of the entire system: functions being supported by the system
Use Case Diagram does NOT indicate data flows or flows of information in and out the system (they are identified later in interaction diagrams)

12. Extension and Abstract Use Cases
An extension use case extends the functionality of an original use case to add new behaviors or actions to the basic course. An extension use case can only be invoked by the use case it is extending.
An abstract use case contains typical course steps that were common to two or more original use cases. An abstract use case reduces redundancy and promotes reuse.

13. Extension Use Cases (“extend” relationship)
Class registration
Registration for special classes
Insufficient prerequisites
“Class registration” is the basic course of actions. On special occasions, “Registration for special classes” and/or “Insufficient prerequisites” will be invoked. Special cases add new data/behaviors to the normal case.

14. Abstract Use Cases (“include” relationship)
Track sales & inventory
Reorder supplies
Generate reports
“Track sales & inventory” includes “Reorder Supplies” and “Generate reports”

15. Inheritance among Actors or Use Cases
Place order
Place order by telephone
Place order via webpage
Client
Sales Representative
Prepare sales report
“Place order by telephone” or “Place order via webpage” are possible types of “Place order” “Sales Representative” plays all roles of “Client”

16. CRUD Use Cases vs. Individual Use Cases
Place order
Client
Salesman
Check order status
Cancel order
DataBase Administrator
Administer warehouse state
CRUD (Create, Read, Update, Delete) type use cases are used when application is meant to store data and one actor interacts with it (e.g. database maintenance, order management, etc.).

17. Use Case Documentation
Each use case should include documentation in the form of scenarios
Scenario is a sequence of actions documenting a behavior
Each use case should have at least the main scenario but it is preferable to include the alternative scenarios as well
Both main and alternative scenarios precisely describe the full functionality represented by a use case
Additional important elements of the use case documentation include: pre-conditions and post- conditions

18. Building a Use Case Diagram
Identify actors (look at the sources and destinations of major inputs and outputs)
Identify use cases (major system functions)
Identify the system boundary
Identify associations between actors and use cases
Identify additional associations between use cases (“extend”, “include”)
Identify inheritance relationships among use cases and actors

19. From business tasks to Use Cases

20. Business task description
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21. Use case diagram
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22. „Make repair reservation” use case specification
Service personnel selects 'Make repair reservation‘
System displays 'repair reservation' form
Service personnel selects client search
System displays list of clients
Service personnel chooses a client
System inserts the client's data into the 'repair reservation' form
Service personnel selects repairs search
Include: Display repair types
Service personnel selects the repair type
System inserts the repair's data together with the cost to the 'repair reservation' form
Service personnel selects 'make repair reservation‘
System displays confirmation
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23. „Make repair reservation” use case extension point
before point 5. extend: Add client
„Add client” use case specification
System displays 'add client' form
Service personnel inserts client's data (name, address, phone number, address)
Service personnel selects 'add client‘
System displays confirmation
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24. Rent-a-Car case study Possible business tasks: Rent a car
Take back the rented car
Prepare cars for rental
Make a reservation for a car
Buy a car
Sell a car …
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25. „Rent a car” business task
Business steps:
Identifying the type of car and rental time frame the client is interested in
Identifying the client
Preparing the rental contract
Signing the contract and informing garage about new rental
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