PETCSM™ (Process of Elimination Through Common Source Method™) is a visual, logic-driven framework designed to identify true root causes swiftly and accurately across IT, engineering, cybersecurity--and any other function. By acting as a logic layer that cuts through the noise of modern system alerts and assumptions, PETCSM™ replaces guesswork with a disciplined mindset rooted in curiosity, neutrality, and pattern recognition. The method focuses on isolating truth through consistency, empowering users to eliminate variables with clarity and move from overwhelming data to actionable solutions with confidence.
The PETCSM™ Mindset
- Curiosity — asking why without fear or bias
- Neutrality — removing ego, blame, and assumptions
- Discipline — documenting what actually happened
- Pattern Recognition — letting evidence reveal the truth
The Six Steps
- Define the Problem
- Gather Evidence
- Select Five Instances
- List Candidate Variables
- Run the 5×5 Test
- Validate the Match
The 5×5 Test
The 5×5 Test compares five variables across five clean instances. Anything not present in all five is eliminated. What remains is your root cause candidate — the one factor that appears every time.
If it’s not consistent, it cannot be the cause.
PETCSM™ + AI
AI generates possibilities. PETCSM™ filters them. Together, they form a Hybrid Intelligence Funnel that moves from noise → logic → truth. AI accelerates the search; PETCSM™ ensures the answer is correct.
GET THE BOOK
Everything you need to learn is in the book. Feel free to use the complimentary tools along with the book.
About the Creator
PETCSM™ was developed by Dr. Eric Lynn David, a cybersecurity and IT professional specializing in pattern‑based troubleshooting, forensic logic, and mindset‑driven analysis. His work blends technical rigor with visual clarity, making complex reasoning accessible to teams, leaders, and learners. Learn more HERE.
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(c) 2026 by Eric L David