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.