Software Testing - Waterfall Model

Waterfall testing refers to software testing done within the Waterfall development model, where testing happens only after the entire development phase is complete — not in parallel with coding.

1. What Is the Waterfall Model?

• A linear, sequential development process.

• Each phase must be completed before the next begins.

• Typical phases: Requirements → Design → Development → Testing → Deployment → Maintenance.

• Testing comes late in the process.

2. How Testing Works in Waterfall

• No testing until coding is finished — test cases are based on completed requirements and designs.

• Testers receive the fully developed product and verify it against the requirements.

• Bugs are reported and fixed before release.

• Any major defect late in the cycle can cause delays or rework.

3. Advantages

• Clear structure and documentation.

• Easy to understand and manage for small projects.

• Works well if requirements are fixed and stable.

• Strong separation of roles (developers vs testers).

4. Disadvantages

• Late testing means defects are found late, making fixes more costly.

• Limited flexibility — changes require going back to earlier phases.

• Not ideal for projects where requirements evolve.

• Delays in development directly delay testing.

5. Waterfall Testing Steps

1. Test Planning — Based on approved requirements and design.

2. Test Case Design — Creating detailed test scripts.

3. Test Environment Setup — Preparing hardware, software, and tools.

4. Test Execution — Running all functional, non-functional, and system tests.

5. Defect Reporting & Fixing — Iterating until major issues are resolved.

6. Test Closure — Documentation and sign-off.

6. Common Testing Types in Waterfall

• Unit Testing (by developers before handoff)

• Integration Testing

• System Testing

• Acceptance Testing