The objective of this article is to propose an improvement for all those companies that have problems of inventories or of maximum stock; Allowing to implement or develop other inventory techniques based on statistical tools. A convenient control of the inventory in an original company or organization an easy procedure of study of the products and to manage the whole level of supply of the products finished to the clients. In this sense, this article proposes the realization by means of the Pareto diagram and the classification ABC, the improvement of inventory in a case of study (a manufacturing company and Comercializadora) that allows seeing the problem of pending orders, sum of quantities Outstanding and the sum of total losses. With this case will identify products that are the little vital and the many trivial in a company fulfilling the theory of Vilfredo Pareto or also known as the 80-20 and the distribution ABC of the products