the 80 20 rule came from vilfredo pareto.
where did the 80 20 rule come from?
vilfredo pareto,
pareto principle









































the pareto principle (also known as the 80/20 rule, the law of the vital few, or the principle of factor sparsity) states that, for many events, roughly 80% of the effects come from 20% of the causes. management consultant joseph m. juran suggested the principle and named it after italian economist vilfredo pareto, who noted the 80/20 connection while at the university of lausanne in 1896, as published in his first work, "cours d'économie politique". in it, pareto showed that approximately 80% of the land in italy was owned by 20% of the population.
pareto principle
the pareto principle is a popular example of such a "law". it states that roughly 80% of the effects come from 20% of the causes, and is thus also known as the 80/20 rule. in business, the 80/20 rule says that 80% of your business comes from just 20% of your customers. in software engineering, it's often said that 80% of the errors are caused by just 20% of the bugs. 20% of the world creates roughly 80% of worldwide gdp. 80% of healthcare expenses in the us are caused by 20% of the population.
empirical statistical laws