1. System Analysis System Analysis - Mr. Ahmad Al-Ghoul System Analysis and Design

2. Avicenna System Analysis and Design System Analysis2 Chapter Objectives Explain how object-oriented analysis can be used to describe an information system Explain how object-oriented analysis can be used to describe an information system Define object modeling terms and concepts, including objects, instances, attributes, methods, messages, and classes Define object modeling terms and concepts, including objects, instances, attributes, methods, messages, and classes

3. Avicenna System Analysis and Design System Analysis3 Introduction Object-oriented (O-O) analysis describes an information system by identifying things called objects. Object-oriented analysis is a popular approach that sees a system from the viewpoint of the objects themselves as they function and interact with the system. Object-oriented (O-O) analysis describes an information system by identifying things called objects. Object-oriented analysis is a popular approach that sees a system from the viewpoint of the objects themselves as they function and interact with the system. Although traditional structured analysis is the most popular approach, the use of object- oriented analysis and design is growing rapidly Although traditional structured analysis is the most popular approach, the use of object- oriented analysis and design is growing rapidly

4. Avicenna System Analysis and Design System Analysis4 Object-Oriented analysis and design using UML The Unified Modeling Language (UML) is used to describe the system concept as a collection of objects incorporating both data and processes The Unified Modeling Language (UML) is used to describe the system concept as a collection of objects incorporating both data and processes UML is just a standard diagramming notation. It is just a tool, not a skill that is valuable in itself. UML is just a standard diagramming notation. It is just a tool, not a skill that is valuable in itself.

5. Avicenna System Analysis and Design System Analysis5 Object-Oriented analysis and design using UML The UML combines the best of the best from The UML combines the best of the best from Data Modelling concepts (Entity Relationship Diagrams) Data Modelling concepts (Entity Relationship Diagrams) Business Modelling (work flow) Business Modelling (work flow) Object Modelling Object Modelling Component Modelling Component Modelling The UML is the standard language for visualizing, specifying, constructing, and documenting the artefacts of a software-intensive system The UML is the standard language for visualizing, specifying, constructing, and documenting the artefacts of a software-intensive system It can be used with all processes, throughout the development life cycle, and across different implementation technologies It can be used with all processes, throughout the development life cycle, and across different implementation technologies

6. Avicenna System Analysis and Design System Analysis6 Object-Oriented analysis and design using UML The UML may be used to: The UML may be used to: Display the boundary of a system & its major functions using use cases and actors Display the boundary of a system & its major functions using use cases and actors Illustrate use case realizations with interaction diagrams Illustrate use case realizations with interaction diagrams Represent a static structure of a system using class diagrams Represent a static structure of a system using class diagrams Model the behaviour of objects with state transition diagrams Model the behaviour of objects with state transition diagrams Reveal the physical implementation architecture with component & deployment diagrams Reveal the physical implementation architecture with component & deployment diagrams

7. Avicenna System Analysis and Design System Analysis7 Object-Oriented analysis and design using UML Object-Oriented Terms and Concepts Object-Oriented Terms and Concepts Object model Object model Object model Object model An object model describes objects, which combine data and processes. Object models are the end product of object-oriented analysis. An object model describes objects, which combine data and processes. Object models are the end product of object-oriented analysis.

8. Avicenna System Analysis and Design System Analysis8 Object-Oriented analysis and design using UML Object-Oriented Terms and Concepts Object-Oriented Terms and Concepts Objects Objects Instances Instances Attributes Attributes Methods Methods Messages Messages Classes Classes

9. Avicenna System Analysis and Design System Analysis9 Object-Oriented analysis and design using UML Objects and Instances Objects and Instances An object represents a real person, place, event, or transaction that are relevant to the system we are analyzing. An object represents a real person, place, event, or transaction that are relevant to the system we are analyzing. An object includes data and the processes that affect that data An object includes data and the processes that affect that data An object has certain attributes, which are characteristics that describe the object. An object has certain attributes, which are characteristics that describe the object. An object has methods, which are tasks or functions that the object performs when it receives a message, or command. An object has methods, which are tasks or functions that the object performs when it receives a message, or command. A group of similar objects are called class A group of similar objects are called class The UML represents an object as a rectangle with the object name at top, followed by the object’s attributes and methods The UML represents an object as a rectangle with the object name at top, followed by the object’s attributes and methods An instance is a specific member of an object or a class An instance is a specific member of an object or a class

10. Avicenna System Analysis and Design System Analysis10 Object-Oriented analysis and design using UML Attributes Attributes If objects are similar to nouns, attributes are similar to adjectives that describe the characteristics of an object If objects are similar to nouns, attributes are similar to adjectives that describe the characteristics of an object Number of attributes depends on the business requirements of the information system and its users Number of attributes depends on the business requirements of the information system and its users Systems analysts define an object’s attributes during the system design process Systems analysts define an object’s attributes during the system design process

11. Avicenna System Analysis and Design System Analysis11 Object-Oriented analysis and design using UML Methods Methods A method defines specific tasks that an object can perform A method defines specific tasks that an object can perform Just as objects are similar to nouns and attributes are similar to adjectives, methods resemble verbs that describe what and how an object does something Just as objects are similar to nouns and attributes are similar to adjectives, methods resemble verbs that describe what and how an object does something

12. Avicenna System Analysis and Design System Analysis12 Object-Oriented analysis and design using UML [1] The DOG object includes six attributes and four methods. The CHILD object includes four attributes and five methods The PARENT object includes five attributes and three methods.

13. Avicenna System Analysis and Design System Analysis13 Object-Oriented analysis and design using UML Messages Messages A message is a command that tells an object or class to perform a creation method A message is a command that tells an object or class to perform a creation method Polymorphism: The concept that a message gives different meanings to different objects depend on the methods Polymorphism: The concept that a message gives different meanings to different objects depend on the methods

14. Avicenna System Analysis and Design System Analysis14 Object-Oriented analysis and design using UML [1] The message ADD STUDENT signals the STUDENT class to perform the ADD STUDENT method the ADD STUDENT method requires the STUDENT object to perform nine specific steps.

15. Avicenna System Analysis and Design System Analysis15 Object-Oriented analysis and design using UML [1] An example of polymorphism, the message GOOD NIGHT produces different results, depending on which object receives it.

16. Avicenna System Analysis and Design System Analysis16 Object-Oriented analysis and design using UML You can view an object as a black box, because a message to the object triggers changes within the object without specifying how the changes must be carried out. The black box concept is an example of encapsulation. You can view an object as a black box, because a message to the object triggers changes within the object without specifying how the changes must be carried out. The black box concept is an example of encapsulation. Encapsulation means that all data and methods are self- contained Encapsulation means that all data and methods are self- contained By limiting access to internal processes, an object prevents its internal code from being altered by anther object or process By limiting access to internal processes, an object prevents its internal code from being altered by anther object or process Encapsulation allows objects to be used as modular components anywhere in the system, because objects send and receive messages but do not alter the internal methods of other objects Encapsulation allows objects to be used as modular components anywhere in the system, because objects send and receive messages but do not alter the internal methods of other objects

17. Avicenna System Analysis and Design System Analysis17 Object-Oriented analysis and design using UML Classes Classes An object belongs to a group or category called a class that is optimal for reuse and maintainability An object belongs to a group or category called a class that is optimal for reuse and maintainability All objects within a class share common attributes and methods All objects within a class share common attributes and methods Objects within a class can grouped into subclass, which are more specific categories within a class Objects within a class can grouped into subclass, which are more specific categories within a class A class can belong to a more general category called a superclass A class can belong to a more general category called a superclass

18. Avicenna System Analysis and Design System Analysis18 Object-Oriented analysis and design using UML [1] the PERSON superclass includes common attributes and methods. EMPLOYEE is a class within the PERSON superclass. INSTRUCTOR is a subclass within the EMPLOYEE class.

19. Avicenna System Analysis and Design System Analysis19 Sequence Summary The unified modeling language (UML) is a widely used method of visualizing and documenting an information system The unified modeling language (UML) is a widely used method of visualizing and documenting an information system UML is just a standard diagramming notation. It is just a tool, not a skill that is valuable in itself. UML is just a standard diagramming notation. It is just a tool, not a skill that is valuable in itself. An object represents a real person, place, event, or transaction that are relevant to the system we are analyzing. An object represents a real person, place, event, or transaction that are relevant to the system we are analyzing. An object includes data and the processes that affect that data An object includes data and the processes that affect that data Object oriented terms include classes, attributes, instance, messages, and methods Object oriented terms include classes, attributes, instance, messages, and methods Classes include objects that have similar attributes, or characteristics Classes include objects that have similar attributes, or characteristics Individual members of a class are called object instances Individual members of a class are called object instances Objects can send massages, or commands, that require other objects to perform certain methods Objects can send massages, or commands, that require other objects to perform certain methods A method defines specific tasks that an object can perform A method defines specific tasks that an object can perform

20. Avicenna System Analysis and Design System Analysis20 Sequence Summary In this Sequence we have In this Sequence we have Defined and explained object oriented analysis Defined and explained object oriented analysis Defined and explained the unified modeling language (UML) Defined and explained the unified modeling language (UML) Defined and explained object oriented terms includes objects, classes, attributes, instance, messages, and methods Defined and explained object oriented terms includes objects, classes, attributes, instance, messages, and methods

21. Avicenna System Analysis and Design System Analysis21 Reference [1] System Analysis and Design, Sixth Edition Authors: Gary B. Shelly, Thomas J. Cashman and Harry J. Rosenblatt Authors: Gary B. Shelly, Thomas J. Cashman and Harry J. Rosenblatt Publisher: SHELLY CASHMAN SEWIES. Publisher: SHELLY CASHMAN SEWIES. [2] system analysis and design, sixth edition Authors: Kenneth E. Kendall and Julie E. Kendall Authors: Kenneth E. Kendall and Julie E. Kendall Publisher: Prentice Hall Publisher: Prentice Hall [3] Modern Systems Analysis and Design Third Edition Authors: Jeffrey A. Hoffer, Joey F. George, Joseph S. Valacich Authors: Jeffrey A. Hoffer, Joey F. George, Joseph S. Valacich Publisher: prentice hall Publisher: prentice hall