Vital Few

Derived from the pareto chart, the term indicates that many defects come from relatively few causes (the 80/20 rule).

For example, 20% of the people in the country make up 80% of the wealth of the country.

Vital Few: These are the few (20%) independent variables (X’s) which contribute to maximum (80%) of the total variation. These are identified through Pareto Charts and Design of Experiments.