The effort for searching, studying and characterizing extrasolar planets and planetary systems is a growing and improving field of astrophysical research. Alongside the growing knowledge on the field, the data resources are also growing, both from observations and numerical simulations. To tackle interoperability of these data, an effort is starting (under the EU H2020 ASTERICS project) to delineate a data model to allow a common sharing of the datasets and collections of exoplanetary data. The data model will pick up model components from the IVOA specifications, either existing or under investigation, and attach new ones where needed. Here are presented the first results in drafting the exoplanetary systems dedicated data model. Relationships are reported with existing and proposed IVOA models; new key components not yet available in the interoperable scenario are shown. The results here reported cover a first set of requirements and considerations and take into account aspects like the observations of exoplanetary systems, the usage of existing exoplanets catalogues, the investigation of atmospheres of confirmed exoplanets and the simulation of exoplanet's atmospheres devoted to characterize exoplanets habitability.