OOAD unit1 introduction to object orientation

Object Oriented Analysis
and Design
Introduction to Object Orientation

 Analysis — understanding, finding and describing
concepts in the problem domain.
 Design — understanding and defining software solution /
objects that represent the analysis concepts and will eventually be
implemented in code.
 OOAD — Analysis is object-oriented and design is object-
oriented. A software development approach that emphasizes a
logical solution based on objects.
What is OOAD?

Knowledge
Representation (in A.I.)
•Psychological Validity
•Philosophical Validity
•Computational Validity
Databases
Emphasis in Persistent
Data (ACID properties)
•Relational DB
•Network DB
•Hierarchical DB
•OODB
Programming
Languages
Emphasis in Efficiency
Simula, SmallTalk, C++,
Protel, Java
ERD
SDM
CM
ADT
ERD: Entity Relationship Diagram
SDM: Semantic Data Model
ADT: Abstract Data Type
CM: Conceptual Model
Why Object-Oriented
- Who’s Behind Object-Orientation
System /
Software
Engineering

How to Do OOAD
OO Prog. Languages
Direct
Programming
OO Design
First designing and
then Program
OO Analysis
Process PerspectiveOO Technology
First we do Analysis (use
case & by UML) and then
designing and at last
computer program
Where are we heading?

Objectives: Introduction to Object Orientation
1. Understand the basic principles of object
orientation
2. Understand the basic concepts and terms of
object orientation and the associated UML
notation
3. Appreciate the strengths of object orientation
4. Understand some basic UML modeling
mechanisms

Abstraction
Encapsulation
Modularity
Hierarchy
Object Orientation
Basic Principles of Object Orientation
Hide implementation from
clients
It separate the external aspect
of an object from the internal
implementation
The breaking up of something
complex into manageable
pieces
Manage level of abstraction
Focus on the essential
Avoid Complexity and
description

Basic Concepts of Object Orientation
 Data: A piece of Information
Or
anything which perform communication
Or
Anything which are the combination of text, characters, digits,
images, video, audio, special characters, special symbols, graphs,
statistics etc
 Information: Its an analyzes form of data
Or
Information is also called the an “Application form of data”)
Analysis
Data (Question & Answers) Information

• Knowledge: It is an act of understanding and Applying the
meaningful data or information
Or
Knowledge is the organized form of data or information that may used
for some useful purposes.
Data Information Knowledge
 Computer Program : A set of computer instructions which are
get executed and provide specific output.
 Software: Software is nothing but the collection of computer
programs that are integrated together (incorporates together ) and
deliver the desired results to its users.
“Software is the collection of objects (Objects are the combinations of Data structure
and its behavior)”

What is Object Orientations:
“Object orientation means Organizing software as a collection of
Discrete Objects that incorporate both Data Structure and Its
Behavior”
1. Class: “A class is the abstraction that describes important properties
to an application and ignore the rest of others”
Or
A class describe a group of objects with
same properties (attributes) & behavior (operations)
kind of relationships
and semantics.Student
Name
Roll No
Add ()
Delete ()
Update ()
Class Name
Attributes
Name
Operations
Class Structure

3.Object: “Its an instance of class or It is the concept, abstraction
or thing with identity that has meaning for an application”
4. Identity: Data is quantized into discrete distinguishable entities
called objects
5. Classification: When an objects with same Data Structure
(attributes) and Behavior (operations or features) are grouped into a
class.
6. Development: Development refers to the overall
construction, production, design and assembling of software
Ram
21
Object
Structure

Object Oriented Development or Properties
1. Inheritance: It is a sharing of Attributes and Operations among classes
based on hierarchical relationship.
2. Polymorphism: Same operations behaves differently for different classes
or situations
3. Encapsulation: also called Information Hiding. It separate the external
aspects of an object from the internal implementation details. So that object can access
only those data which is allowed by encapsulation
4. Operation: An operation is a procedure or transformation that an object
perform or subject to.
Operation modify the values of operand or transform it into another state or value.
Operation may also the combination of operand and operator.
5. Method: It is a systematic arrangement or Sequence of implementation of an
operations. Or Implementation of an operations in specific way.
6. Procedure: Sequential of execution instructions or procedures.

Planning
Data Collection
Analysis
Designing
Development
Testing
Implementation &
Deployment
Software Development life Cycle – SDLC
Find Goal, Objectives, Purpose and do all planning
Data Collection / gathering from all sources
Analyze the gathered data and prepare UML, SRS.
Design DB, Front End, H/W and Interfaces
Do Programming & Coding, Write Source Code
Test code, design, interface. Find bug, error, fault
Deploy the SW to customer & do support

Object Oriented Methodology
Domain Model: Describe real
world objects referred to
system
Application
Model:
Describe part of
system which
are visible to
users
•Architecture
•UML Diagrams
•Database & Schema
•Front End / Interfaces /
Services
•Forms / Windows /NW
Connection

Three Model Concept
1. Class Model: It describe the static structure of the Object in a system
and their relationships, identity, attributes & operations
Class Diagram: It is graph which nodes and classes and arcs are
relationships.
Or
“It is a type of static structure diagram that describes the structure
of a system by showing the system's classes and their attributes,
operations (or methods), and the relationships among objects.
The purpose of the class diagram can be summarized as −
• Analysis and design of the static view of an application.
• Describe responsibilities of a system.
• Base for component and deployment diagrams.
• Forward and reverse engineering.

2. State Model: It describe an aspect of the object that change over a
time.
State Diagram: It is a graph in which nodes are states and arcs are
transactions between the states caused by events.
Or
State diagrams are used to give an abstract
description of the behavior of a system.
Following are the main purposes of using State chart diagrams −
To model the dynamic aspect of a system.
To model the life time of a reactive system.
To describe different states of an object during its life time.
Define a state machine to model the states of an object.
State Diagram

3. Interaction Model: It describe “ How an Object in a system
cooperate to achieve the desired result”
or
“ Interaction Model describe interaction between objects. i.e How an
individual object collaborate to achieve the behavior (operation) of a system”
Object Interaction Object
(DOB) (Age on present date) today's date
Use Cases: It focus on the functionality of the system.
Means what system can do for users
what system can deliver to users.
Sequence Diagram: It shows the object interaction and the time slice
of their interactions.
Mean it present the Sequential Interactions of Program/Object.
Activity Diagram: It shows or Present important Processing Steps.

Object Oriented Themes
1. Abstraction: Show only Essential things and hide or ignore the
details
2. Encapsulation: Hiding the information from unauthorized
access.
3. Sharing: Also called it an Inheritance. Both Data Structure and
behavior can share with subclasses or with child
4. Importance of an object: Importance on an object depends
on Application (uses of system) and often changes happens during
the developments. (S/W development DS & Procedure are more imp than
functional development methodologies)
5. Synergy: A collective work of more than one things or objects.
(when only one object is there then efficiency is calculated but when more
than one objects are there then collective efficiency are considered which is
called synergy [efficacy])

Modeling
Model: “It is defined as the representation of a system for the purpose of
studying the system”
Simulation: “It is a process of creating and analyzing the prototype of
physical model to predict the performance of actual system in the real
world”
Need of Modeling / Phases of Modeling/ Purpose of Modeling
1. Testing the Physical Entity before building
Modeling and simulation “Generate huge amount of information which required to
design and build an actual system”
2. Communication with customers
• It identify the “Need, Expectation and Requirement” of customers /consumers
• It generate Row Data for analysis and SRS (documentation of system)
3. Visualization
• It shows how Ideas / Concepts flows
• It improve the creativity level
4. Reduction of Complexity
Reduce the complexity and make it user friendly

Link & Association
1. Link: A link is a physical or Conceptual Connection among Objects
Two Object – Binary Association
Three Objects- Ternary Association
Four or more Objects – N-ary Association
2. Associations: An association is a description of a group of links
Or
If there are group of links are available between objects to objects or
classes to classes then such group of links are called an Association
• The Link of an association connect objects from the same classes
• An association describe a set of potential links, in the same way that a class
describe the potential objects

Key Points: Links & Associations
1. To show link in UML, we used LINE.
2. A link is relationship among objects.
3. If link has name then it should be UNDERLINED.
4. An association connects the classes and objects and it also denoted by LINE.
5. The Association name is optional if the model is unambiguous.
6. Association are hierarchically bidirectional.
7. Developer often used an association in programming languages as references
from one object to another.
8. A REFERENCE is an attribute in one object that refers to another object.
9. Association are important because they break ENCAPSULATIONS
10.Association never be a private to the class because they transcend the
classes.

3. Multiplicity: It specify the number of instances (objects) of one class may
relates to instances (objects) of an associated class.

Multiplicity Specify the Participation of an Objects in an Associations

4. Association End Name:
• Sometime it specify the role of objects or classes in an association
• It has two ends
• Association end names are mandatory for association between two
objects of same class.

5 . Ordering:
Mostly an objects have no order in an association that’s why
ordering help to maintain their specific order in an associations

6 . Bag and Sequence
A Bag is a collection of Elements (Duplication Allowed)
A Sequence is an Ordered collection of Elements (Duplication Allowed)

7 . Association Classes:
An Association class is an Association that is also a class.
The Instance of an association class derive identity from instances of the
constituent classes.

8 . Qualified Association:
An qualified associations is an associations in which an attribute called
QUALIFIER disambiguates the object from many association ends .
A qualified association has a qualifier that is used to select an object
(or objects) from a larger set of related objects, based upon the
qualifier key.

9. Generalization & Inheritance:
Generalization:
• It’s a relation between super class and child class
• It organize classes by their similarities, differences and structuring the
description of objects
• It is a process to make more general form of class
• It is also called “Is-A” relationship

Key Points: Generalization:
1. Generalization is transitive across arbitrary number of levels.
2. The term ANCENSTOR and DESCENDENT refers to generalization of
classes across multiple levels.
3. An instance of a subclass is also the instance of super class
4. An instance can invoke the any operations of an ancestor class
5. Each subclass may free to access the function from ancestor classes but also
have free to add their own functions too.

Uses of Generalization:
1. It support to Polymorphism.
2. It increases the flexibility of software
3. It provide description of an object
4. It formed the taxonomy (the branch of science concerned with
classification, especially of organisms, systematic) & organize the objects
on their similarities and differences
5. It enable the reuse of code
6. It also allow to adjust the code
7. It provide Specialization (opposite to generalization)
8. Specialization refers to the fact that subclass refined or specialize the super
class
9. Generalization is generalize the subclass.

Object Constraints Language –OCL
OCL uses these sequence to traverse the class model
1. Attributes
2. Operations
3. Simple Association
4. Qualified Association
5. Association Classes
6. Generalization / Specialization
7. Filters

Customer
Name
Phone No
Credit Card
Max Limit
Balance
Bank
IFSC Code
MICR Code
Statement
Payment
Date
Payment
Amt.
Transaction
Date
Amount
Mailing
Address
Per. Address
Contact No.
Statement
Date
Account
No
Payment Vendor
Processing
Fees
Discount
Merchant
Bank
Transacti
on
Number
1 * 0..1 1
*
*
1
0..
1
0..
1
1
*
*
Class Diagram of Banking Transaction for Credit
Card

OOAD unit1 introduction to object orientation

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