1. System Analysis and Design
- Mr. Ahmad Al-Ghoul
In this sequence we will continue discussing the Object-Oriented analysis and design using UML, we will Describe class diagrams, sequence diagrams, state transition diagrams, and activity diagrams

2. System Analysis and Design System Analysis
Learning Objectives
Describe Unified Modeling Language (UML) tools and techniques, including class diagrams, sequence diagrams, state transition diagrams, and activity diagrams
Explain how to organize an object model
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System Analysis and Design System Analysis

3. Object-Oriented analysis and design using UML
Class Diagram
A class is a collection of objects with common structure, common behaviour, common relationships, and common semantics.
A class diagram represents a detailed view of single use case
Show the classes that participate in the use case
Document the relationship among the classes
Class diagram is a logical model, which evolves into a physical model and finally becomes a functioning information system
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System Analysis and Design System Analysis

4. Object-Oriented analysis and design using UML
Class Diagram
A class is drawn as a rectangle with the class name at the top
Classes should be named using the vocabulary of the domain
Naming standards should be created
The class’s attributes
The class’s methods
Lines show relationship between classes and have labels identifying the action that relates the two classes
When you construct the class diagram, the first step is to review the use case and identify the classes that participate in the underlying business transaction
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System Analysis and Design System Analysis

5. Object-Oriented analysis and design using UML
Cardinality describes how instances of one class relate to instance's of anther class
Examples of UML notations that indicate the nature of the relationship between instances of one class and instances of another class. [1]
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6. Object-Oriented analysis and design using UML
Class diagram for a sales order use case (attributes and methods omitted for clarity).
Notice that the sales office has one sales manager who can have anywhere from zero to many sales rep.
Each sales rep can have anywhere from zero to many customers, but each customer has only one sales rep
[1]
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System Analysis and Design System Analysis

7. Object-Oriented analysis and design using UML
The use case diagram presents an outside view of the system
Interaction diagrams describe how use cases are realized as interactions among societies of objects
Sequence diagrams, state transition diagrams, and activity diagrams are dynamic modeling tools that can help a systems analyst understand how objects behave and interact with the system.
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System Analysis and Design System Analysis

8. Object-Oriented analysis and design using UML
Sequence Diagrams
A sequence diagram is a dynamic model of a use case
Sequence diagrams show classes interactions arranged in a time sequence
A sequence diagram graphically documents the use case by showing the classes, the messages, and the timing of the messages
specified by the flow of events.
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9. Object-Oriented analysis and design using UML
Sequence diagrams include symbols that represent
Classes
Lifelines
Messages
Focuses
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10. Object-Oriented analysis and design using UML
Classes
A class is identified by a rectangle with the name inside.
Classes that send or receive messages are shown at the top of the sequence diagram
Lifelines
A lifeline is identified by a dashed line
The lifeline represents the time during which the object above it is able to interact with the other objects in the use case
An X marks the end of the lifeline
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11. Object-Oriented analysis and design using UML
Messages
A message is identified by a line showing direction that runs between two objects
The label shows the name of the message and can include additional information about the content
Focuses
A focus is identified vertical shape that covers the lifeline
The focus indicates when an object sends or receives a message
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12. Object-Oriented analysis and design using UML
The sequence diagram for the ADD NEW STUDENT use case. [1]
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13. Object-Oriented analysis and design using UML
State Transition Diagrams
A state transition diagram shows how an object changes from one state to another, depending on events that affect the object
A state transition diagram shows
The life history of a given object
The events that cause a transition from one state to another
The actions that result from a state change
In a state transition diagram, the states appear as rounded rectangles with the state names inside
The small circle to the left is the initial state
The lines show direction and describe the action or event that causes a transition from one state to anther
The circle at the right with a hollow border is the final state
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14. Object-Oriented analysis and design using UML
An example of a state transition diagram for a bank account.
A bank account could be opened as NEW or EXISTING account, and eventually become a CLOSED or FORMER account
Anther possible state for a bank account could be FORZEN, if the account’s assets are legally attached
[1]
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System Analysis and Design System Analysis

15. Object-Oriented analysis and design using UML
Activity Diagrams
An activity diagram resembles a horizontal flowchart that shows the actions and events as they occur
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16. Object-Oriented analysis and design using UML
Activity represented as rounded rectangles.
Activities are typically action states, it goes automatically to the next state after the action is complete.
The filled in circle represents the start
Transitions shown as arrows show how you move from activity to activity
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System Analysis and Design System Analysis

17. Object-Oriented analysis and design using UML
An activity diagram shows the actions and events involved in withdrawing cash from an ATM machine.
Notice that the customer initiate the activity by inserting an ATM card and requesting cash
[1]
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System Analysis and Design System Analysis

18. Object-Oriented analysis and design using UML
Organizing the Object Model
Each diagram or object definition should be supported by clear, relevant documentation that can be accessed easily by anyone who reviews the object model
You should organize your use cases and use case diagrams so they can be linked to the appropriate class, state transition, sequence, and activity diagrams
Your diagrams and documentation are the foundation for the system’s design
It is much easier to repair a diagram now than to change the software later
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19. System Analysis and Design System Analysis
Sequence Summary
A class diagram represents a a detailed view of a single use case, showing the classes that participate in the underlying business transaction, and the relationship among class instances, which is called cardinality
A sequence diagram is a dynamic model of a use case, showing the interaction among classes during a specified time period
Sequence diagram include lifelines, messages, and focuses
A state transition diagram shows how an object changes from one state to anther, depending on events that affect the object
An activity diagram resembles a horizontal flowchart that shows actions and events as they occur in a system
At the end of the object modeling process, you organize your use cases and use case diagrams and create class, sequence, state transaction, and activity diagrams
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System Analysis and Design System Analysis

20. System Analysis and Design System Analysis
Sequence Summary
In this Sequence we have
Explained and described how to draw different UML diagrams including class diagrams, sequence diagrams, state transition diagrams, and activity diagrams
Defined the terms lifelines, messages, and focuses
Explained how to organize your use cases and use case diagrams and create class, sequence, state transaction, and activity diagrams
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System Analysis and Design System Analysis

21. System Analysis and Design System Analysis
Reference
[1] System Analysis and Design, Sixth Edition
Authors: Gary B. Shelly, Thomas J. Cashman and Harry J. Rosenblatt ,
Publisher: SHELLY CASHMAN SEWIES.
[2] system analysis and design, sixth edition
Authors: Kenneth E. Kendall and Julie E. Kendall
Publisher: Prentice Hall
[3] Modern Systems Analysis and Design Third Edition
Authors: Jeffrey A. Hoffer , Joey F. George, Joseph S. Valacich
Publisher: prentice hall
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