How does the Waterfall SDLC model support quality assurance?

In my professional experience, I've been part of Waterfall SDLC projects, including a notable one involving an Online Banking system for a large financial institution. We began with a well-defined business case and meticulous business requirement documentation. Next, we moved into the design phase, where the architecture, user interfaces and data flows of the system were carefully designed. Coding followed adhering strictly to the requirements, with testing starting only after development. We followed the standard testing process, ensuring quality. User Acceptance Testing (UAT) and approvals proceeded smoothly. Deployment was smooth and maintenance phase was efficient, thanks to the well-documented architecture.

Leading the test phase for an Online Banking System project following the Waterfall approach, testing commenced after development was concluded. Meticulously documented was a test plan, encompassing system, integration, acceptance, and usability testing across various browsers and mobile devices, with clear entry & exit criteria. The documentation also covered traceable test cases, including negative scenarios. A detailed defect log tracked identified bugs, including actions taken, screenshots, reproducibility instructions, priority and severity. Post-testing, outcomes were summarised in a concise test report. This approach ensured that the system met high standards of functionality, performance, and security.

In my experience, the Waterfall model offers a few advantages for QA: 1. Well-defined requirements upfront can reduce misunderstandings. 2. The sequential phases align with QA activities. 3. Dedicated testing phase allows for early issue identification. 4. Comprehensive documentation ensures transparency and traceability. 5. Early stakeholder involvement aligns QA efforts with business goals. 6. Minimised scope changes simplify QA planning. 7. Well-defined timelines aid QA planning. 8. Encourages documenting best practices and lessons learned. 9. Suits industries with strict regulatory compliance requirements. 10. Enforces rigorous testing (retesting & regression testing)for quality assurance.

In my experience, while the Waterfall approach has merits, it can hinder flexibility and delay product launches. I recall a project where articulating evolving business needs posed challenges. During requirements documentation, new functionalities, improvements & innovations kept emerging. Testing later revealed defects that early detection could have avoided. Misunderstood requirements led to incorrect implementations, and extensive documentation became impractical. Emerging tech rendered the original product obsolete, ultimately not meeting evolving business needs. This experience highlights the importance of adaptability & flexibility in today's fast-paced business world, where longer timelines and higher costs can threaten success.

I have worked more than one projects which followed Waterfall SDLC model. Some advantages according to me are : 1. More time available for testing 2. Sufficient time to develop test plan, test cases 3. Less probability of scope creep 4. Defect triage will be helpful in updating/adding new test cases 5. Exploratory testing can be done along with system testing 6. Lessons learnt from previous release can be implemented in next cycle 7. Automation - Detailed feasibility analysis, tool selection, POC all can be done in a cycle. I felt more comfortable in the waterfall model as a beginner tester ??

Each of the Software Development Life Cycle (SDLC) models has its place, depending on the project's context and the organisation's business strategy and maturity. Therefore, selecting the appropriate model should be a well-considered decision. It's important to note that a model that works effectively for one product may not necessarily align with the needs of another product. Additionally, while the Waterfall model has its merits, it may not be suitable for all projects, especially those in rapidly changing environments or industries. Project managers and teams typically make this decision based on the specific requirements and constraints of their projects.