Software Development Life Cycle (SDLC)

The Software Development Life Cycle (SDLC) is a structured process that software developers follow to design, develop, test, and deploy high-quality software. It helps ensure efficiency, security, and scalability while reducing risks and costs.

Phases of SDLC

1. Planning & Requirement Analysis

✅ Purpose: Identify project goals, scope, and feasibility.
✅ Key Activities:

Gather business and user requirements.
Define project scope, objectives, and constraints.
Perform feasibility studies (technical, financial, operational).
✅ Outcome: Software Requirement Specification (SRS) document.

2. System Design

✅ Purpose: Create the blueprint of the software.
✅ Key Activities:

Define software architecture and data models.
Choose technology stack (languages, databases, frameworks).
Create UI/UX wireframes and system workflows.
✅ Outcome: High-level & low-level design documents (HLD & LLD).

3. Implementation (Coding & Development)

✅ Purpose: Convert design into working software.
✅ Key Activities:

Developers write and compile code.
Use version control systems (Git, GitHub, GitLab).
Follow coding standards and best practices.
✅ Outcome: Source code and executable software.

4. Testing & Quality Assurance (QA)

✅ Purpose: Identify and fix defects to ensure reliability.
✅ Key Activities:

Unit Testing – Testing individual components.
Integration Testing – Verifying communication between modules.
System Testing – Checking overall system functionality.
User Acceptance Testing (UAT) – Validating software with users.
✅ Outcome: Bug-free, stable software ready for deployment.

5. Deployment

✅ Purpose: Release the software to users.
✅ Key Activities:

Deploy software on production servers.
Configure databases, security settings, and network infrastructure.
Use CI/CD pipelines for automated deployment.
✅ Outcome: Live software available to users.

6. Maintenance & Support

✅ Purpose: Ensure long-term stability and improvements.
✅ Key Activities:

Fix bugs and security vulnerabilities.
Release software updates and new features.
Monitor system performance and user feedback.
✅ Outcome: Continuously improved and secure software.

SDLC Models (Methodologies)

Different approaches exist for implementing SDLC:

Waterfall Model – Linear, sequential approach (good for small, well-defined projects).
Agile Model – Iterative, flexible approach with regular updates (used in modern software development).
Scrum – Agile framework with short sprints (2-4 weeks).
DevOps Model – Combines development and operations for continuous integration/deployment (CI/CD).
V-Model (Validation & Verification) – Testing is done parallel to development.
Spiral Model – Combines iterative development with risk management.

Why is SDLC Important?

✔ Ensures structured and efficient development.
✔ Reduces risks, errors, and security vulnerabilities.
✔ Improves software quality and maintainability.
✔ Helps manage time, budget, and resources effectively.