Abstract One way to reduce costs in companies is decreasing inventory levels and improving the value flow. In the present case study a production line where automotive door seals are manufactured was analyzed. First, an analysis with the use of value stream mapping was undertaken in order to identify processes and a material flow. The current state and future state maps were developed. Then, these maps were used to prepare the model of the production system, of which dynamics have been analyzed with the use of Vensim software. As the results, the dynamics of inventory levels along with the manufacturing system were obtained.