Vocational education and training (VET) systems around the world serve many aims, the most important of which can be grouped into three main aims: economic, social and educational aims. These different aims find their roots in different socio-cultural and economic contexts and their importance in the functioning of the systems evolves according to the times. Our contribution proposes a reflection on the centrality of the notion of aims in order to better understand and describe the functioning of VET systems. By adopting an exploratory approach based on discourse analysis, we will show the interest in using this notion to build a theoretical framework that facilitates international comparisons between VET systems and also the description of their evolution from the past to the future. To exemplify the relevance of this exploratory approach, the contribution will propose a description of the evolution of the Swiss VET system from 1880 up to 2030, based on the articulation of economic, social and educational aims.