Inventories are essential for any company, in the case of commercial companies, inventories are the support of their main activity: the purchase and sale of products. Poor inventory management, as well as a null or poor
inventory policy, can lead to loss of money, loss of customers, or even bankruptcy, raising the question of whether there is a way to obtain an ideal inventory policy for microenterprises and to determine the economic impact of such a policy. This article proposes the use of discrete event simulation to analyze the impact of changes in different scenarios for inventory policies in the Veterinary "El Trébol", and thus determine an adequate policy for the revision of vaccines, to have the lowest average price as possible.