1. Provenance Metadata for Shared Product Model Databases Etiel Petrinja, Vlado Stankovski & Žiga Turk University of Ljubljana Faculty of Civil and Geodetic Engineering Chair of Construction Informatics

2. Provenance Metadata for Shared Product Model Databases2/14 Index Basic facts about provenance What are ontologies? Provenance in the IFC standard Provenance ontology Provenance service prototype

3. Provenance Metadata for Shared Product Model Databases3/14 What is Provenance? Provenance data is usually Metadata: –intended for sharing, retrieving, integrating, aggregating and processing. –generated with the hope that it is comprehensive enough to be future-proofed. –recorded for those who we do not yet know will use the object and who will likely use it in a different way. –machine computational: free text is of limited help. Provenance is the knowledge that makes –An item interpretable and reusable within a context –An item reproducible or at least repeatable. Its part of the information model of any system

4. Provenance Metadata for Shared Product Model Databases4/14 Provenance data elements Legal – Who is responsible? Professional – Why does it have such value? Managerial – Who is doing the work here? Re-use – Can we re-use the process next time we do something similar? Trust Preservation Security Scalability Generality Customisability Provenance data requirements Other

5. Provenance Metadata for Shared Product Model Databases5/14 Provenance Granularity Different levels of granularity correspond to different use-cases Knowledge level (annotations-free text or in a structured/semi-structured form) Organization level (organization name, author name…) Product or Process level (which workflow has been used and how) Data level (derivation paths of data results from services)

6. Provenance Metadata for Shared Product Model Databases6/14 Ontologies An ontology is an engineering artefact: –It is constituted by a specific vocabulary used to describe a certain reality –Plus a set of explicit assumptions regarding the intended meaning of the vocabulary Thus an ontology describes a formal specification of a certain domain: –Shared understanding of a domain of interest –Formal and machine manipulative model of a domain of interest Language - OWL language(s): Application - Protege

7. Provenance Metadata for Shared Product Model Databases7/14 IFC standard and provenance The main entity connected with provenance issues in the IFC standard is the IFCOwnerHistory entity It is linked to the IFCRoot entity and thus inherited by every single entity of the IFC standard that has IFCRoot as its highest ancestor IFCOwnerHistory entity has several sub entities with different attributes: –ifcAuditTrail (7) –ifcApplication (3) –ifcOrganization (4) –ifcAddress (13) –ifcPersonAndOrganization (4) –ifcPerson (6)

8. Provenance Metadata for Shared Product Model Databases8/14 Provenance ontology We have inserted in our ontology some concepts that were already present in the IFC standard If we use the OWL notation for specifying ontologies, we have a lot of APIs and other tools that are already implemented and available For a more precise cover of the conceptualisation regarding provenance, some additional rules, axioms, concepts and properties should be added

9. Provenance Metadata for Shared Product Model Databases9/14 Provenance prototype Ontology management: Jena toolkit Separate ontology concepts/properties and instances files Aggregation of smaller ontologies into bigger one Scalability problems with long IFC files Persistent storage in a MySQL database

10. Provenance Metadata for Shared Product Model Databases10/14 Provenance prototype reasoning Ontology Ontology Service Service API Ontology ApplicationReasoner Reasoner sits outside the Ontology Service. Requests are answered w.r.t. the basic facts asserted in the ontology. Ontology Service Service API Application Reasoner Reasoner sits inside the Ontology Service. Requests are answered w.r.t. the semantics. Ontology

11. Provenance Metadata for Shared Product Model Databases11/14 Provenance prototype architecture

12. Provenance Metadata for Shared Product Model Databases12/14 Web user interface

13. Provenance Metadata for Shared Product Model Databases13/14 Discussion Converting part of the IFC standard into an ontology? Standardising the provenance saving mechanisms and elements Specifying the level of granularity of the provenance metadata Implementing a more general provenance service

14. Provenance Metadata for Shared Product Model Databases14/14 Questions ???