A general rule of thumb in business that says that 20% of the items produce 80% of the action ‐‐ 20% of the product line produces 80% of the sales, 20 percent of the customers generate 80% of the complaints, and so on. In evaluating any business situation, look for the small group which produces the major portion of the transactions you are concerned with. This rule is not exactly accurate, but it reflects a general truth, nothing is evenly distributed.