The 24th International Steelmaking Days of ATS (Association Technique de la Sidérurgie) took place on the 10th and 11th of December 2003 in Paris. More than 650 experts coming from 24 countries all over the world attended the congress. For flat products, 27 reports were presented and discussed concerning hot rolling, cold rolling and surface coating. The reports show that progress in hot and cold rolling technology requires close cooperation between production, research and development, as well as with the revamping team and the plant supplier. Highlights of the papers are measures for increasing the availability of the plant, optimization of yield and quality, cost-effective production and sustainability.