The Pareto principle (also known as the 80/20 rule, the law of the vital few and the principle of factor sparsity) states that for many outcomes, roughly 80% of consequences come from 20% of causes
After reading the writings of Italian sociologist and economist Vilfredo Pareto, management consultant Joseph M. Juran refined the notion in 1941 in the context of quality control and improvement. Pareto demonstrated in his first book, Cours d’économie politique, that 20% of the population in the Kingdom of Italy held about 80% of the land. The Pareto efficiency and the Pareto principle are only loosely connected.
I have consistently applied the Pareto Principle to guidance and decision-making throughout my life.
Recognize that 20% of your activities are currently responsible for 80% of your difficulties.
Furthermore, 80% of your problems can be attributed to 20% of your clients! It is possible that 20% of your attention accounts for even 80% of your satisfaction.
Finally, 20% of suppliers account for 80% of inventory. 20% of your future is impacted by 80% of your weekly responsibilities. 20% of the individuals in your life are responsible for 80% of your grief. More examples here.