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Test Coverage

Test Coverage is a measure of how much of the application’s requirements, functionality, and risk areas are validated by testing.

Test coverage answers: “How much of the system have we actually tested?”

1. Definition

Test Coverage is a measure of how much of the application’s requirements, functionality, and risk areas are validated by testing.

2. Purpose of Test Coverage

  • Ensure all requirements are tested
  • Identify untested areas
  • Assess testing completeness
  • Reduce release risk
  • Provide transparency to stakeholders

3. Types of Test Coverage (Manual Testing)

3.1 Requirement Coverage

  • Percentage of requirements covered by test cases
  • Tracked using RTM

Example:

  • 95 of 100 requirements tested → 95% coverage

3.2 Functional Coverage

  • Features or modules tested
  • Ensures business workflows are validated

3.3 Test Case Coverage

  • Test cases executed vs planned

3.4 Risk Coverage

  • High-risk areas tested first and thoroughly

3.5 Scenario Coverage

  • Business scenarios and edge cases covered

4. How Test Coverage Is Measured (Manual)

  • Requirement Traceability Matrix (RTM)
  • Test case execution reports
  • Coverage dashboards (manual tracking)

5. Manual Tester’s Role

  • Map test cases to requirements
  • Ensure no requirement is left uncovered
  • Update coverage status regularly
  • Highlight coverage gaps
  • Support release decisions

6. Test Coverage vs Test Execution

Aspect Test Coverage Test Execution
Focus Scope tested Results
Measure Completeness Pass/Fail
Question What is tested? Did it pass?

7. Common Coverage Gaps

  • Missing negative scenarios
  • Untested error handling
  • Ignored non-functional requirements
  • Skipped regression areas

8. Common Misconceptions

  • 100% coverage = defect-free ❌
  • High coverage guarantees quality ❌

Coverage shows what was tested, not how well it was tested.

9. Real-Time Example

Before release:

  • Functional coverage: 100%
  • Requirement coverage: 98%
  • Risk coverage: All high-risk areas tested

This indicates high test confidence.

10. Interview-Ready Answers

Short answer:

Test coverage measures how much of the application has been tested.

Detailed answer:

Test coverage indicates the extent to which requirements, features, and risk areas are validated by testing to assess completeness and release readiness.

11. Key Takeaway

Test Coverage provides visibility into testing completeness, helping teams understand residual risk.