In order to the Brazilian steel mills to become international competitors, it is fundamental to introduce new management concepts, with a broader view, without internal and external frontiers, such as the Supply Chain Management concept. This view diverges from a previous conception, which restrained to the logistics the basic material administration and distribution functions. With the Supply Chain Management, the business standpoint increases and comprises the whole supply chain, from the raw material supplier up to the customer and the consumer. The research aims to show, by means of a case study from Companhia Siderúrgica Nacional, its dynamic within the supply chain, using the Supply Chain Management Model of Cooper, Lambert and Pagh. The structure of the aforementioned model is supported on three pillars: management components, business processes and structure of the supply chain. From the mentioned pillars of the model, this research emphasizes the description of the business processes and the identification of the sub-processes, as well as their relationships with groups of internal functions of Companhia Siderúrgica Nacional (CSN), considering that CSN does not take part in any managed supply chain. The results of the research show that it is possible to identify the dynamics of Companhia Siderúrgica Nacional within the supply chain, detecting the strong points, in and the need to implement actions aimed to improve the management components highlighted in the model. The proposed corrective actions would contribute to increase the profitability and optimize the service level and the utilization of its resources within the supply chain in which CSN is included.