POC / POO (Point of Cause / Point of Occurrence)

The specific location, process step, or moment in time where a defect or problem is actually created or introduced. Also called Point of Occurrence (POO). Different from Point of Detection (POD) where the problem is discovered, and Escape Point where it should have been caught. Understanding POC is essential for effective root cause analysis—fixing detection points prevents escapes but doesn't eliminate the problem at its source. Example: defect created during welding (POC) but discovered during final inspection (POD). Root cause analysis must trace back to POC to implement permanent corrective actions.