80-20 Rule and Pareto Diagram

The 80-20 rule (also known as the Pareto principle) states that 80% of the problems in the system come from 20% of the causes. Alternatively, by eliminating 20% of the system’s deficiencies, 80% of the system’s problems can be solved. The rule is based on calculating the frequency of incidents that cause most of the problems.
Pareto charts are often used to present the data and make decisions about corrective actions based on the 80-20 rule.
Pareto charts represent the type or category of causes ordered by frequency of occurrence.