Operational safety is at the center of all companies' concerns because increasing productivity is the top priority. Moreover, the high cost of breakdowns invests in a maintenance strategy, one of the most critical aspects of a manufacturing system. In the digital age, e-maintenance platforms can interoperate technically but fail to achieve semantic interoperability. The results are ambiguities and misunderstandings that can lead to equipment shutdowns or inefficient use of material resources. However, as formal knowledge specifications, ontologies have successfully integrated heterogeneous systems for some time. Therefore, the authors developed a core industrial maintenance ontology that is both generic and capable of extending and refining to meet semantic information repository requirements. Ontologies can unite and merge different datasets without adapting new ontologies. Only the core ontology needs to be modified according to the new semantics. A detailed description of the development process is provided, beginning with the definition of requirements and ending with the evaluation.