When a physical assembly fails in the field, quality teams must react instantly. Jumping to quick fixes without identifying the root cause ensures the issue will reappear in future production batches.
Root-cause analysis requires a structured, scientific approach. Teams must isolate variables and recreate failures under controlled conditions to find the mechanical or process fault.
"Do not patch a failure; find the root variables that allowed it to occur, and update your design bounds."
Ishikawa (Fishbone) Isolation
The Fishbone diagram categorizes potential causes into Materials, Machines, Methods, Measurement, Mother Nature, and Manpower. Brainstorming across these categories prevents teams from assuming the first explanation is correct.
The 5 Whys
Asking 'Why' five times digs beneath symptoms. If a screw stripped, why? The torque tool setting was high. Why? The calibration schedule was missed. Why? The database tracking calibration failed. Fixing the tool calibration process solves the root variable.