Introduction
SDLC (Software Development Life Cycle) and STLC (Software Testing Life Cycle) are structured processes followed during software development and testing. STLC is a part of SDLC.
What is SDLC?
SDLC is the overall process followed to develop high-quality software. It covers planning, designing, development, testing and deployment.
- Requirement Analysis
- System Design
- Development
- Testing
- Deployment
- Maintenance
What is STLC?
STLC is the testing process within SDLC that ensures software quality. It defines structured testing phases.
- Requirement Analysis
- Test Planning
- Test Case Development
- Test Environment Setup
- Test Execution
- Test Closure
Phase Mapping Between SDLC and STLC
- SDLC Requirement Analysis → STLC Requirement Analysis
- SDLC Design Phase → STLC Test Planning
- SDLC Development → STLC Test Case Creation
- SDLC Testing Phase → STLC Execution
- SDLC Deployment → STLC Closure
STLC vs SDLC – Comparison Table
| Criteria | SDLC | STLC |
|---|---|---|
| Full Form | Software Development Life Cycle | Software Testing Life Cycle |
| Focus | Software Development | Software Testing |
| Objective | Build Software | Ensure Quality |
| Scope | Entire project lifecycle | Testing activities only |
| Responsible Team | Developers & Stakeholders | QA/Testers |
Real-Time Example
Example: E-commerce Website
- SDLC: Plan website, design UI, develop code, test and deploy.
- STLC: Analyze requirements, create test cases, execute tests, report defects.
Interview Questions
Difference between STLC and SDLC?
SDLC covers complete development lifecycle, while STLC focuses only on testing phases.
Is STLC part of SDLC?
Yes, STLC is a subset of SDLC.
Which comes first, SDLC or STLC?
SDLC starts first, and STLC runs parallel during development phases.
Frequently Asked Questions
Can STLC exist without SDLC?
No, STLC is part of SDLC.
Why is STLC important?
It ensures systematic testing and improves product quality.