Bug Root Cause Analysis: Current Situation, Scenarios, and a Four‑Step Improvement Process

After ten years of experience in various companies, the author observes that most testing workflows lack a dedicated bug root‑cause analysis stage, typically following a simple cycle of bug submission, developer fix, test verification, and report generation.

Common reasons for this omission include time pressure, insufficient skills, poor communication, lack of tools, low priority, missing processes, absent feedback mechanisms, and overlooking deeper causes.

The content targets bugs discovered during post‑release data‑flow testing across multiple systems, summarizing around 50 bugs to identify underlying patterns.

The proposed four‑step approach consists of:

1. Recording – Log bugs in an Excel sheet (see image).

2. Marking Defect Causes – Add a column for cause analysis, consulting developers when needed.

3. Role Attribution – Classify responsibilities mainly between developers (e.g., lack of self‑testing, insufficient integration) and testers (e.g., missed tests, limited business understanding). Specific examples include duplicate method names, outdated production files, interface misuse, logic errors, incomplete test cases, and poor mutual understanding.

4. Improvement Plans – Suggestions include detailed test cases, clearer result descriptions, consistent page naming, maintaining a feature‑tracking spreadsheet, using fresh baseline data for end‑to‑end flows, adding source‑data modification procedures, and mandating bug‑cause entry in Redmine.

In conclusion, the author encourages a mindset of continuous improvement: document each issue, analyze its root cause, and apply lessons learned to grow testing competence and overall software quality.