This research is part of the ONTODIC project carried out by the TecnoLeTTra team at the Universitat Jaume I in Castellón. ONTODIC aims at developing a systematic methodology for the elaboration of onomasiological terminological dictionaries using an ontology editor. The nature of the conceptual class “activity” is complex, because actions can only be carried out using entities. In our research we have focused on the analysis of the conceptual relationships established by industrial processes (activities) in the field of ceramics. First, the conceptual nature of industrial processes is analysed. Second, we define argumental and circumstantial relations, in which one of the elements linked by the relation belongs to the conceptual class “activity”. Then, we present a case study of the concept “cocción” (firing) in the context of ceramic industry and finally, we put forward some concluding remarks about the formalization of the relationships established by processes using the ontology editor Protégé.