The main results of the current work are the following: An ad hoc OO query facility has been developed for data in CAD systems.
A query result can be exported to a CAD system using an ISO standardized format (STEP Part 21).
By means of the exportation facility the result of a query can be visualized or analyzed through a CAD
system.
A model completion algorithm is implemented for extending a query result such that it becomes a model acceptable by a CAD system. The mediator facilities permit queries combining CAD data with other types of data.
The model completion algorithm is driven by the STEP/EXPRESS information model complemented by
two system tables. One prioritizes possible geometric shape models, and the other resolves ambiguous paths between types in the information model.
Possible future work includes: Implementation of remaining EXPRESS features as functions, procedures, etc., needed for constraint checking. The constraints in STEP standards would
complement but not replace our model completion system tables. Investigation of the ability to specify queries with functions that make advanced calculations over engineering data. The foreign function mechanism of Amos II can be used for this purpose. Enhancing performance by developing new data representations and indexing techniques for complex EXPRESS data structures.