Root Cause on the Floor — 5-Why and Fishbone

Learning objectives

• Get past symptoms
• Build shared understanding of causes

Steps

1. State the defect precisely
2. Ask why five times
3. Cluster causes: man, machine, material, method, environment
4. Pick one root cause and one countermeasure

Factory example

Uneven hem — the '5-why' led to a machine tension issue, not operator skill; a mechanic fix removed the defect.

Common mistakes

• Stopping at operator blame
• No countermeasure ownership