Common Cause Variation
Quality
Common Cause Variation
Natural variation inherent in a stable process and generated by the system as currently designed.
Examples
- 01The fill weight of 500 g bags varies by about 2 g due to common cause variation in the powder density and the dosing screw.
- 02In a supplier meeting, both sides agree the remaining scatter is common cause variation, so improvement needs a process change, not more operator instructions.
- 03Management stops asking for an explanation of every daily dip once the team shows the chart reflects only common cause variation.