Institute for Healthcare Improvement
According to the "Pareto Principle," in any group of things that contribute to a common effect, a relatively few contributors account for the majority of the effect. A Pareto chart is a type of bar chart in which the various factors that contribute to an overall effect are arranged in order according to the magnitude of their effect. This ordering helps identify the "vital few" — the factors that warrant the most attention.
Using a Pareto chart helps a team concentrate its efforts on the factors that have the greatest impact. It also helps a team communicate the rationale for focusing on certain areas.