Role of QA in SDLC & STLC
Overview
Quality Assurance (QA) plays a critical role throughout the Software Development Life Cycle (SDLC) and has its own lifecycle called the Software Testing Life Cycle (STLC). As a senior QA engineer, understanding the integration points between QA activities and each SDLC phase is essential for ensuring delivery of high-quality software that meets both business and technical expectations.
Role of QA in SDLC
SDLC outlines the entire journey of software development, from concept to delivery and maintenance. QA is no longer limited to the "testing phase"—modern QA integrates into each phase of SDLC to apply the Shift-Left Testing approach.
SDLC Phases and QA Involvement:
| SDLC Phase | QA Responsibilities |
|---|---|
| Requirement Analysis | - Review requirements for clarity and testability - Identify ambiguities and missing cases - Contribute to requirement traceability |
| Design | - Participate in design reviews - Identify high-risk areas - Define high-level test scenarios and environment needs |
| Implementation | - Collaborate with developers - Begin test case creation in parallel - Support unit testing efforts |
| Testing | - Execute test cases (manual/automated) - Perform exploratory and regression testing - Report and manage defects |
| Deployment | - Validate release readiness - Conduct smoke/sanity tests - Coordinate sign-off |
| Maintenance | - Perform post-release validation - Monitor production issues - Update regression suite accordingly |
Software Testing Life Cycle (STLC)
STLC is a subset of SDLC and focuses entirely on the testing process. It defines a structured approach for all testing activities, from planning to test closure.
STLC Phases:
-
Requirement Analysis
- Identify testable requirements
- Understand business use cases and flows
-
Test Planning
- Define scope, resources, schedule
- Identify risk and mitigation plans
- Choose test tools and environments
-
Test Case Development
- Design and write test cases and scripts
- Prepare test data
-
Test Environment Setup
- Configure systems, networks, and tools
- Validate environment readiness
-
Test Execution
- Run test cases (manual and automated)
- Log defects, retest, and track issues
-
Test Closure
- Prepare test summary reports
- Analyze metrics (e.g., defect density)
- Conduct lessons learned or retrospectives
QA as a Bridge in SDLC
As a QA Engineer, especially in a senior role, your value increases when you:
- Act as a bridge between developers, business analysts, and stakeholders
- Advocate for preventive quality, not just defect detection
- Promote automation, CI/CD integration, and test-driven development
Summary
QA is not a gatekeeper—it’s a continuous, collaborative role embedded throughout SDLC. By following STLC and participating in each SDLC phase, QA ensures software is reliable, maintainable, and aligned with user expectations.
Tip: Use traceability matrices and test coverage reports to demonstrate QA's impact across the lifecycle.