🔎 What is Root Cause Analysis (RCA)?

Root Cause Analysis is a problem-solving method used in software testing (and many other fields) to identify the main reason why a defect or issue occurred—instead of just fixing the symptoms.

Think of it this way:

• Bug = Symptom
• Root Cause = Disease

If you only fix the bug, the problem may return. But if you remove the root cause, you prevent similar issues in the future.

⚙️ Common Techniques in RCA

1. 5 Whys → Keep asking “Why?” until you reach the real cause.
2. Example: Login not working → Server error → Server overloaded → No load testing → Requirement gap.
3. Fishbone Diagram (Ishikawa) → A Visual way to find causes under categories like People, Process, Tools, Environment.
4. Pareto Analysis (80/20 rule) → 80% of defects often come from 20% of causes. Focus on the key ones.

✅ Example in Testing

Bug: User can log in without entering a password.

• Why? → No password validation in code.
• Why? → Developer skipped implementation.
• Why? → Requirement document didn’t mention it.
• Root Cause: Missing requirement in SRS.

🎯 Benefits of RCA in QA

• Prevents repetitive bugs.
• Improves software quality long-term.
• Saves time and cost on rework.
• Strengthens requirement analysis and processes.