Pareto Chart

A Pareto Chart is a bar chart of discrete data that displays the most significant categories of defects in descending order. The chart was named after the Italian economist, Vilfredo Pareto, who discovered the “80/20 Rule.” The Pareto Chart uses the “80/20 Rule” to narrow the focus of process improvement to the 20% of defect categories causing 80% of the process issues.

Pareto Charts display both frequency of occurrences (bar graph) and cumulative percent of occurrences (line graph) on a single chart. The left Y-Axis shows frequency of occurrences, while the right Y-Axis shows the total percentage.