Download - 5-Object Oriented Analysis (Object Oriented Software Engineering - BNU Spring 2017)

Object Oriented Analysis

FROM: HAFIZ AMMAR SIDDIQUI – COURSE: OBJECT ORIENTED SOFTWARE ENGINEERING – INSTITUTE: BEACONHOUSE NATIONAL UNIVERSITY

Static Models


Static Models■ Represents the static elements of a system

■ Explains the structural organization of a system

■ Describes the static structure of objects that exist in the problem domain

■ Time independent view of system

■ Static modelling includes– Use case diagram– Class diagram– Object diagram– Component diagram– Deployment diagram


Static Models (Object Model)


Object Model■ System is modelled using object oriented techniques

■ Classified into different stages1. Analysis object model2. System design object model3. Object design model


Static Models (Class Diagram)


Class Diagram■ Class diagram is a static model diagram which is modelled using the UML (Unified

Modeling Language)

■ Show classes which are abstractions that specify the common structure, attributesand behaviors of a set of objects

■ Describes the structure of a system by using classes and objects, and therelationships among them

■ Used from data modeling of a specific domain to a detailed design of the system


Object Modelling using UML


Object Modelling using UML■ Object modelling technique– An object modeling approach for software modeling and designing– Method for analysis, design and implementation using object oriented principles

■ UML (Unified Modeling Language)– An industry standard modeling language with a rich graphical notation, andcomprehensive set of diagrams and elements

– A modeling language use to specify, design and develop the document artifacts of asoftware system

– Used to analyze, design and implement a system using the methods of objectoriented software engineering

– Combine different approaches in a single design language


The process of developing class diagram


The process of developing class diagram■ Steps of developing a class diagram1. Identify set of classes2. Define relationships between classes3. Add attributes and behaviors4. Iterate over the process again till class diagram is satisfactory


Class Diagram UML (Class)■ Class is represented with a box that contain three compartments, top compartment

contains the name of a class, the middle compartment contain the attributes of aclass, and lower compartment contain the behaviors of a class


Class_Name

visibility attribute_name : data_type

visibility behavior_name (input_parameter : data_type) : return_type

Class Diagram UML (Association)■ Association relation is represented by a line from one class to another class and its

multiplicity is represented by a numerical range at the both ends of a line


Class_Name

<attributes list>

<behaviors list>

Class_Name

<attributes list>

<behaviors list>

min_no … max_no(* for Infinite)


Class Diagram UML (Aggregation)■ Aggregation relation is represented by hollow diamond shape on the containing

class with a single line that connects it to the contained class and its multiplicity isrepresented by a numerical range at the both ends of a line


Class_Name

<attributes list>

<behaviors list>

Class_Name

<attributes list>

<behaviors list>



Class Diagram UML (Composition)■ Composition relation is represented by filled diamond shape on the containing class

with a single line that connects it to the contained class and its multiplicity isrepresented by a numerical range at the both ends of a line


Class_Name

<attributes list>

<behaviors list>

Class_Name

<attributes list>

<behaviors list>



Class Diagram UML (Inheritance)■ Inheritance relation is represented by hollow triangle shape on the base class end of

the line that connects it to the derived class


Class_Name

<attributes list>

<behaviors list>

Class_Name

<attributes list>

<behaviors list>

Dynamic Models


Dynamic Models■ Represents the dynamic elements of a system

■ Explains the behavior of a system

■ Shows the order of events and messages that occur in a system

■ Describes the interaction among objects and flow of information

■ Time dependent view of system

■ Dynamic modelling includes– Interaction diagram– Sequence diagram– State machine diagram– Activity diagram


Dynamic Models (Sequence Diagram)


Sequence Diagram■ Sequence diagram is a dynamic model diagram which is modelled using the UML

(Unified Modeling Language)

■ Describes the objects participating in a use case

■ Explains that how different parts of a system interact with each other to carry out aspecific task

■ Shows the dynamic behavior of interacting objects

■ Explains that how objects communicate with one another and in which order

■ Shows the messaging between objects arranged in a time sequence

■ Models the collaboration of different objects with respect to time


Sequence Diagram UML■ Every participating object has its own lifeline which is represented by a vertical

dotted line drawn either under a rectangular box or human symbol (if object is actor)

■ If an object is destroyed, cross is drawn on bottom of the lifeline

■ Messages exchanged between objects are represented by horizontal arrows, in theorder in which they occur, synchronous messages with solid arrow heads andasynchronous messages with open arrow heads

■ Request or invocation messages are represented by solid lines and response orreturn messages are represented by dotted lines

■ Processes performed in response to messages are represented by activation boxes,which are opaque rectangles drawn on top of lifelines

■ Loops, alternative flows or reference to another sequence are represented inside alarge rectangle over the lifelines of related objects


Sequence Diagram UML


Object_Name

Actor_Name

Object_Name

X

Request_Msg_Sync Request_Msg_Create_Sync

Response_Msg

Request_Msg_Delete_Async

Request_Msg_Async

Self_Msg

Reference■ Object Oriented Software Engineering: Using UML, Patterns, and Java by Bernd

Bruegge, Allen H. Dutoit, Prentice Hall, 2010
