Using object-oriented information modelling approach, we structure the data as a hierarchy of objects which are defined using the notions of the class, attribute, and syntax, and the mechanisms of introducing class inheritance, grouping of attributes into packages, defining mandatory and optional attributes.

The distinguished feature of the information model is time-awareness, a generic capability to assign a validity period to the attribute value, which provides for modelling of how object characteristics evolve over time.

Expressing the meta-data that describes the information model in the same object-oriented form as regular data, storing both data and meta-data in the same repository, and providing access to both types of data using the same services, we provide an extandable model allowing system administrators and even ordinary system users to enrich the information model at run-time by defining new object classes and attributes.