In this article, we analyze the devolution process (Brousseau, 1990) of an extra-mathematical problem whose resolution requires the implementation of one or more modelling processes in the sense of Blum and Leiss (2007). We focused on the “Eiffel Tower” problem in two classes of 14-year-old students with two teachers. We analyze its implementation using the theoretical tool developed by Yvain-Prébiski (2021) integrating the cognitive component in the sense of Borromeo Ferri (2006).