Software Development Lifecycle (SDLC): End-to-End Overview

What is UML?

UML stands for Unified Modeling Language.

It is a standard visual language used to design and document software systems.

UML diagrams help teams visualize system structure and behavior.

Why UML is Used

• It Communicate design ideas clearly
• It helos to Visualize system structure
• It helps to Document architecture
• It Simplify complex systems

Common UML Diagrams

Some commonly used UML diagrams include:

1. Use Case Diagram

2. Class Diagram

3. Sequence Diagram

4. Activity Diagram

5. State Diagram

In SDLC design phase, the most commonly used ones are:

1. Use Case Diagram

2. Class Diagram

3. Sequence Diagram

Use Case Diagram

What is a Use Case Diagram?

A Use Case Diagram shows how users interact with a system.

It identifies Actors (users or external systems) and Use cases (actions performed)

Components

1. Actor: Represents a user or external system interacting with the application.

2. Use Case: Represents a functionality of the system.

3. System Boundary Defines the system being designed.

Example

Actors:

• Student
• Instructor
• Admin

Use Cases:

• Register
• Login
• Enroll in Course
• Upload Course

Class Diagram

What is a Class Diagram?

A Class Diagram represents the structure of the system by showing classes, attributes, methods, and relationships.

It is one of the most important diagrams in object-oriented design.

Components

1. Class: It contains Attributes (data) and Methods (functions).

Example

Class: Student:

• studentId is a attribute
• name is a attribute
• email is a attribute

Methods

• Register
• enrollCourse()
• viewCourses()

Sequence Diagram

What is a Sequence Diagram?

A Sequence Diagram shows how different components interact with each other over time.

It describes the order of operations in a system.

Components

1. Actor: User interacting with the system.

2. Objects System components

3. Messages Communication between components

Example: User Login Process

• User enters credentials
• Frontend sends request to API
• API validates user
• Database returns user data
• API returns responser