Database model for design data

A construction database model (CDM) used for the conceptual level modeling of design objects is presented. A primary purpose of the CDM model is the modeling of hierarchically structured objects and construction dependencies among objects. CDM is an attribute-based data model. The CDM model represents various abstractions identified in certain semantic database models by means of attributes. To distinguish between different abstractions, the notion of attribute role is introduced. Special attention is paid to the representation of derived properties of the object. They are described by means of a constructor. The constructor makes possible the description and reevaluation of the design object construction process. The CDM is used as a data model for a storage system designed for storing data in CAD applications.