Pareto's Principle - The 80-20 Rule
Also known as Pareto's Principle, the 80/20 Rule says that 20 percent of something always are responsible for 80 percent of the results. Twenty percent of the agents sell eighty percent of the properties; twenty percent of the products have eighty percent of the flaws. Quality Management pioneer, Dr. Joseph Juran, called the phenomenon "vital few and trivial many". The article Pareto's Principle - The 80-20 Rule explains the 80/20 Rule in more detail and tells how you can use it to more effectively manage many different aspects of your life.
Use caution when you apply this principle. Remember it is a "principle" not a "law", but it is a good way for managers to stay focused on the few important issues and not get lost in the volume of information and tasks that try to take over our days.
I’ve already heard a comment about this principle also being applied in business relationships: 20% of coleagues are resposible for 80% of your problems!!! Even when they leave, other 20% will take their place, so… keep focused and don’t give the more importance than they deserve!