The Approach to Develop the Foundation Data Model published in March 2021 follows up on the Survey of Top-level Ontologies (TLO) published in November 2020.
It sets out the Top-Level-Ontology requirements for the NDT's Foundation Data Model. Drawing upon the assessment of the TLOs listed in the Survey of Top-level Ontologies, it identifies 4 potential candidates for the NDT’s TLO: BORO, IDEAS, HQDM and ISO 15926-2:
The four candidates are distinct from the other TLOs in being 4-dimensionalist, i.e. they consider individual objects as four-dimensional, with both spatial and temporal parts.