Lean Manufacturing and Six Sigma Definitions

Glossary terms, history, people and definitions about Lean and Six Sigma

Vilfredo Pareto

Share This

Vilfredo Federico Damaso Pareto (born Wilfried Fritz Pareto, 15 July 1848 – 19 August 1923) was an Italian engineer, sociologist, economist, political scientist, and philosopher. He made several important contributions to economics, particularly in the study of income distribution and in the analysis of individuals’ choices, which resulted in the Pareto principle and Pareto chart.

The Pareto principle (also known as the 80/20 rule, or the law of the vital few and trivial many) is a popular prioritization method used in process improvement, to focus the limited resources on the problems with the most potential impact.

Examples of the Pareto principle:

  • Fixing the top 20% of the most-reported software bugs would eliminate 80% of the related errors and crashes in a system
  • The top 20% of manufacturing defects would reduce the total quality issues by 80%
  • 20% of workout exercises and habits have 80% of the impact for the trainee
  • 20% of the office area in a building uses 80% of the electricity
  • 20% of the sales team brings in 80% of the total sales
  • 20% of the football team scores 80% of the points
  • 20% of the people own 80% of the total money
  • 20% of the residents in a city consume 80% of the water
  • 20% of the hazards cause 80% of the injuries or accidents
  • 20% of the webpages account for 80% of the site traffic
  • 20% of patients use 80% of health care resources

By displaying the data in a Pareto chart, the 80/20 rule can be easier to identify.


  • Adam Smith



lean six sigma certification and training

Additional Resources

« Back to Glossary Index