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Defect / Bug Report

A Defect (Bug) Report is a formal record that documents an issue found during testing, describing how the actual behavior differs from the expected behavior.

A defect report answers: “What is wrong, where, and how to reproduce it?”

1. Definition

A Defect (Bug) Report is a formal record that documents an issue found during testing, describing how the actual behavior differs from the expected behavior.

A defect report answers: “What is wrong, where, and how to reproduce it?”

2. Purpose of a Defect / Bug Report

  • Communicate issues clearly to developers
  • Enable quick reproduction and fixing
  • Track defect status and resolution
  • Maintain quality and accountability

3. Key Components of a Defect Report

A well-written defect report includes:

  • Defect ID
  • Title / Summary
  • Module / Feature
  • Environment
  • Build Version
  • Steps to Reproduce
  • Expected Result
  • Actual Result
  • Severity
  • Priority
  • Status
  • Attachments (screenshots, logs)

4. Severity vs Priority

Aspect Severity Priority
Meaning Impact of defect Urgency to fix
Set by Tester Product/Business
Example App crash Fix immediately

5. How to Write an Effective Defect Report

  • Be clear and concise
  • Use simple language
  • Provide exact steps
  • Include evidence
  • Avoid assumptions or blame

6. Real-Time Example

Defect: Login button not clickable

  • Steps:
    1. Open login page
    2. Enter valid credentials
    3. Click Login
  • Expected: User logged in
  • Actual: Nothing happens

7. Defect Lifecycle (Preview)

  • New
  • Assigned
  • Open
  • Fixed
  • Re-tested
  • Closed / Reopened

(Covered separately in Defect Life Cycle topic.)

8. Common Defect Types

  • Functional defects
  • UI defects
  • Performance issues
  • Security gaps
  • Data issues

9. Common Mistakes

  • Vague descriptions
  • Missing steps or data
  • Incorrect severity/priority
  • No screenshots

10. Interview-Ready Answers

Short answer:

A defect report documents an issue found during testing with steps to reproduce and expected versus actual results.

Detailed answer:

A defect or bug report is a structured document used to communicate software issues to developers for analysis, fixing, and tracking.

11. Key Takeaway

A good defect report saves time, reduces confusion, and improves collaboration.