Bug Life Cycle and Defect Management

What is a Software Bug?

Any deviation from requirements: wrong output, crash, broken link, confusing message. All bugs get logged, triaged, fixed and verified.

Bug Life Cycle

New -> Assigned -> Open -> Fixed -> Retest -> Verified -> Closed. Side states: Reopen (fix failed), Duplicate, Rejected (not a bug), Deferred (fix later).

Severity vs Priority

• Severity - technical impact: crash on checkout is Critical.
• Priority - business urgency: typo on the homepage can be High priority but Low severity.
• High severity plus low priority: crash in an unused report. Low severity plus high priority: logo wrong on launch day.

How to Write a Good Bug Report

Title: Checkout shows Rs.0 total for 2 items
Steps: 1. Add 2 x Book 2. Open cart 3. Click checkout
Expected: total Rs.998 | Actual: total Rs.0
Env: Chrome 126, staging, user@test.com
Evidence: screenshot + console log attached

Defect Leakage and Density

• Leakage - defects escaping to production; lower is better.
• Density - defects per module; hotspots need more tests or refactoring.

Root Cause Analysis

For every escaped defect ask why five times: wrong total because discount applied twice because coupon logic ran on each item. Fix the cause, add a regression test, share the lesson.

Key Points

• Severity is impact; priority is scheduling.
• One bug report proves one bug with evidence.
• Every production bug earns a regression test.