"Focus on the Significant Few Versus the Trivial Many"
Juran, a key quality leader, made Pareto's 80/20 Popular.
In any analysis 80% of the results are caused by 20% of the incidents. For Pareto in 1900 Italy, 80% of the wealth in each State was in the hands of 20% of the people. 80% of your revenue comes from 20% of your customers
For analysis use a Pareto Diagram
To learn, follow this link