Although inventory management has significantly developed in the past years as a management discipline, its application is still minimal in the service industry and government. In contrast it is an important tool for any company that is running a competitive business. The management of some companies considers inventory as an asset, not a liability. In addition, in companies in which the use and application of inventory models are common, they can still experience inventory problems. This paper analyzes the weakness of the traditional and most popular inventory model: The Economic Order Quantity model (EOQ). Many of the inventory models available are difficult to understand because they are based on complicate mathematical and statistical formulas. The benefits that computer software have simplifying the use of mathematical formula are diminished because some of them do not include special applications or solutions when a variation in the assumption of the models is present. When a company implements the Just in Time philosophy (JIT), the management of inventory does not rest in complex formulas. Inventory experts need to emphasize the application of the models instead of the statistical derivation. They also need to be more aggressive in making managers, students and government authorities more aware of managing the inventory levels effectively. The responsibility of good inventory levels is not the sole task of the Operations Department, but the obligation of all the people in a company. Good inventory levels are now a measure of business competitiveness. The goal must be to increase the service level and at the same time reduce the inventory investment.