Pareto principle

The Pareto principle (alternatively known as Pareto's law, the 80/20 rule, the law of the vital few, or the principle of factor sparsity; hereinafter, the Principle) is the hypothesis that roughly 80% of the effects come from 20% of the causes in many cases.

The concepts of Pareto efficiency and Pareto charts have derived from the Principle.

Definition

According to Managing Quality by Foster (6th edition),

Pareto's law (the 80/20 rule). States that 80% of the problems are a result of 20% of the causes.