OO Development Process

📘 Object-Oriented (OO) Development Process

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🔹 1. Definition

The Object-Oriented Development Process is a step-by-step method used to develop software by applying object-oriented principles such as classes, objects, inheritance, and encapsulation.

👉 Simple idea: It describes how a system is built using objects, from understanding requirements to final implementation.

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🔹 2. Overview of the OO Development Process

Requirements → Analysis → Design → Implementation → Testing → Maintenance

Each phase transforms the system from an idea into a working product.

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🔹 3. Phases of OO Development ⭐

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🔸 3.1 Requirements Gathering

Goal: Understand what the user needs.

🔹 Activities:

• Collect requirements from stakeholders
• Identify system goals
• Define scope

Output:

• Requirement Specification Document

Example: Library system → Users want to issue and return books

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🔸 3.2 Object-Oriented Analysis (OOA)

Goal: Identify key objects and system behavior.

🔹 Steps:

1. Identify actors
2. Identify use cases
3. Identify classes/objects
4. Define relationships

Output:

• Use Case Diagram
• Conceptual Class Diagram

Diagram Description: Actors (stick figures) interacting with system functions (ovals)

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🔸 3.3 Object-Oriented Design (OOD)

Goal: Convert analysis into detailed system design.

🔹 Steps:

1. Define class structure
2. Add attributes & methods
3. Design object interactions
4. Apply design principles

Output:

• Class Diagram
• Sequence Diagram
• Activity Diagram

Diagram Description: Classes represented as boxes with attributes and methods

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🔸 3.4 Implementation (Coding)

Goal: Convert design into actual code.

🔹 Activities:

• Write code using OOP languages (Java, C++, Python)
• Implement classes and methods

Example:

class Book {
  String title;
  void issue() {}
}

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🔸 3.5 Testing

Goal: Ensure the system works correctly.

🔹 Types:

• Unit Testing
• Integration Testing
• System Testing

Purpose:

• Find and fix errors

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🔸 3.6 Maintenance

Goal: Improve and update system after deployment.

🔹 Activities:

• Fix bugs
• Add new features
• Optimize performance

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🔹 4. Iterative Nature of OO Development

👉 Important Concept:

The OO process is iterative and incremental, not strictly linear.

• You may revisit earlier phases
• System improves step by step

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🔹 5. Key Concepts Used in the Process

• Abstraction → Simplify system
• Encapsulation → Protect data
• Inheritance → Reuse code
• Polymorphism → Flexible behavior

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🔹 6. Example (Library System)

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🔹 Step 1: Requirements

• Issue book
• Return book

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🔹 Step 2: Analysis

• Objects: Book, Member, Librarian

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🔹 Step 3: Design

Class: Book
- title
- author
+ issue()
+ return()

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🔹 Step 4: Implementation

• Write code for Book class

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🔹 Step 5: Testing

• Check if issue/return works

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🔹 7. Advantages of OO Development Process

• Better planning and structure
• High reusability
• Easy maintenance
• Scalable systems
• Real-world mapping

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🔹 8. Important Rules / Guidelines

• Always start with clear requirements
• Identify objects carefully
• Use UML diagrams
• Maintain low coupling, high cohesion
• Test continuously

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🔹 9. Likely Exam Questions

1. Define OO Development Process.
2. Explain phases of OO development.
3. What is Object-Oriented Analysis?
4. Differentiate OOA and OOD.
5. Explain iterative nature of OO development.
6. What is the role of testing in OO process?
7. Describe implementation phase.
8. Explain maintenance with examples.
9. Draw OO development lifecycle diagram.
10. Advantages of OO development process.

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🔹 10. Quick Revision Summary 🧠

• OO Development = Building software using objects step-by-step

• Phases:

  • Requirements
  • Analysis
  • Design
  • Implementation
  • Testing
  • Maintenance

👉 Remember Trick: "RADITM" (R → Requirements, A → Analysis, D → Design, I → Implementation, T → Testing, M → Maintenance)

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