A Tool for Intelligent Conceptual Modelling



ICOM is an advanced conceptual modelling tool, which allows the user to design multiple ER or UML class diagrams with inter- and intra-model constraints, expressed in a rich view language similar to OCL and relational algebra (based on the DLR description logic). Logical reasoning is employed by the tool to verify the specification, infer implicit facts, devise stricter constraints, and manifest any inconsistency, with a provably complete inference mechanism. Completeness of reasoning means in this context that no valid deduction is left out by the inference engine. This of course holds for the full data model employed by ICOM, which is much richer than the basic class diagram languages.

The leverage of automated reasoning to support the domain modelling is enabled by a precise semantic definition of all the elements of the class diagrams. The diagrams and inter-model constraints are internally translated into a description logic- based logic formalism. The same underlying logic enables the use of a view definition language to specify additional constraints, not captured at the diagram level.

The conceptual modelling language supported by ICOM can express:

  • the standard Extended Entity-Relationship data model or the standard UML class diagrams (we are working on providing ORM as well), enriched with disjoint and covering constraints and definitions attached to classes and relations by means of view expressions over other classes and relationships in the ontology;
  • inter-ontology mappings, as inclusion and equivalence statements between view expressions involving classes and relationships possibly belonging to different ontologies.
The tool allows for the creation, the editing, the managing, and the storing of several interconnected ontologies, with a user friendly graphical interface. The main purpose of the ICOM project is not to provide to the ontology community a robust tool potentially replacing the many other tools available; we do not claim that ICOM is currently more usable than any of the existing conceptual modelling tools for ontology design. ICOM is meant to be a proof of concept, willing to showcase two main points:
  • the effectiveness of using a class diagram graphical syntax for expressing ontologies, even with complex languages;
  • the emphasis to general entailment, as opposed to just subsumption (classification) and consistency.
ICOM is a fairly mature project, its first release has been published in 2000. The version 3.0 of the ICOM tool is loosely based on the ICOM tool previously released in 2000 as an Entity-Relationship editor (which had around 3,000 registered installations, mostly in academic environments and for teaching purposes in industry), and a demo of a preliminary version was presented few years ago. The foundations of the user-computer interaction have been radically changed according to the experience of the first ICOM and the research in this last decade. The system has been completely re-implemented, using different graphic libraries. The graphical interface has been completely rewritten to improve the usability and intuitiveness of the tool. Interoperability with other tools is a crucial aspect; so, import and export modules have been developed for XMI 2.x and Description Logics based ontology languages via DIG.

The ICOM tool is written in standard Java 5.0, and it is distributed on Linux, Mac, and Windows machines. ICOM communicates via the DIG 1.1 protocol with a description logic server, such as, for example, RACER. ICOM provides an interface for exporting ontologies in OWL format, and for importing and exporting ontologies in UML-XMI class diagrams format.

ICOM reasons with (multiple) diagrams by encoding them in a single description logic knowledge base, and shows the result of any deductions such as inferred links, new stricter constraints, and inconsistent entities or relationships. Theoretical results guarantee the correctness and the completeness of the reasoning process. To the best of our knowledge, this is the first implemented tool for EER conceptual modelling with a provably complete inference mechanism for consistency checking and for deduction -- i.e., derivation of implied links and constraints in the schema. Completeness of reasoning means in this context that no valid deduction is left out by the inference engine. This of course holds for the full data model employed by ICOM, which is much richer than EER. The system employs the DLR description logic to encode the schemas and to express the views and the constraints.

Enrico Franconi - ()