Applying Semantic Web Technology to the Life Cycle Support of Complex Engineering Assets

1. Applying Semantic Web Technology to the Life Cycle Support of Complex Engineering Assets David Price and Rob Bodington david.price@eurostep.com ISWC 2004

2. Agenda • What is Product Life Cycle Support? • Implementing PLCS • The Requirements and Approach for Reference Data • Future use of full Semantic Web capabilities • Sources of Reference Data • Pilot Project • Conclusions

3. What is PLCS? • ISO 10303-239 Product Life Cycle Support, part of STEP • Information model for system integration and data exchange • PLCS scope is “support” of complex assets (e.g. ships) • Configuration Management : As-Designed, As-Realized, As-Maintained • Support Engineering : Support Required (activities, tasks, resources) • Resource Management : Spares, Who/what/when • Maintenance and Feedback : Failures, Replacements, … • Life cycle measured in decades • 80-90 percent of the cost of a ship to UK MoD is after delivery

4. What is STEP? • Formally, ISO 10303 Product data representation and exchange • Written in ISO EXPRESS, an OO-style language roughly equivalent to UML Static Class Diagrams • Commonly called STEP – Standard for the exchange of Product Model Data • Not something new, first STEP parts reached International Standard status in 1994 • STEP scope is vast and varied • under development for 15+ years • Ship Moulded Forms, Printed Circuit Boards, Finite Element Analysis, Systems Engineering, …

5. The Approach to the PLCS standards • In ISO, standardize flexible information model • ability to classify using external classes is built into the model • 200 PLCS information model concepts require Reference Data • Outside ISO, standardize user guides and Reference Data • OASIS PLCS Technical Committee formed for this purpose • US DoD, UK MoD, BAE Systems, DNV, Norwegian Defence, FMV, Boeing, LockheedMartin, Saab, Rolls Royce, Pennant, Eurostep, and LSC Group are members • Enable non-standard Reference Data extensions • Enables further tailoring and contracting for PLCS-based exchange between partners

6. PLCS Requirements ISO Information Model OASIS Reference Data

7. Basic PLCS Implementation Scenario translate to PLCS translate from PLCS XML exchange document MMS HUMS classification Health and Usage Monitoring System on board a ship Maintenance Management System Linked Reference Data Libraries

8. What to do about Reference Data? • UK MoD contracted Eurostep to do a survey of candidates for Reference Data • Definition of Reference Data • The semantics required to complete an information model for use in data exchange scenarios • Goal • Determine best approach for PLCS Reference Data • Scenario • Automating failure reporting using PLCS-based data exchange • Technical Assumptions • Exchange based on PLCS EXPRESS->XML Schema • Enable inclusion and reference to Reference Data • Standard Reference Data is extended in implementing organization

9. RD requirements arising … • Define RD and relationship to PLCS information model • Need class hierarchy, properties and the associated documentation • Easy browsing and operational use on Web and in internal applications • Formally relate organization-specific extensions to standard RD • Integrate extensions into standard RD over time, as appropriate • Enable Net-Centric implementation • Support for very large Reference Data Libraries • Support XML-based exchange • Support Reference Data to be embedded, exchanged or referenced • Support addition of business rules and constraints

10. Recommendations • After reviewing OASIS, OMG, W3C and ISO standards, decided OWL was best fit for requirements and community • Also recommended RD developers use a specific set of tools to minimize risk • Stanford University Protégé with OWL plug-in • Pre-loaded a template containing PLCS schema, high level RDL, etc. for RD developers • Approach approved by OASIS PLCS TC in March 2004

11. Why this approach? • OWL satisfies RD modeling requirements • Class, multiple inheritance, properties, datatypes, instances, reuse of models • EXPRESS modelers understand base concepts already • OWL satisfies the IT requirements • Has an XML syntax, Web enabled, can map to RDBMS • Aligns with ISO standards having potentially reusable Reference Data • ISO 15926 Oil and Gas data warehouse standard • Other factors • Industry and academic support and open-source tools available • Large community with no STEP knowledge know OWL

12. PLCS Ontologies When Deployed XML exchange document classification Reference Data for Organization Editors MoD-rdl-extensions import subClassOf Reference Data for PLCS Users (read-only) plcs-rdl Reference Data for PLCS Editors plcs-refdata PLCS EXPRESS as OWL (read-only) subClassOf plcs-express Dublin Core Elements and Terms (read-only) plcs-dc plcs-dcterms

13. The EXPRESS/RD OWL Relation PLCS Schema Classes RD Classes subClassOf PLCS Schema Classes

14. Benefits to OWL approach • For business processes and rules, reasoners and related technology have potential use • While PLCS data exchange isn’t “Semantic Web”, approach lays the foundation for future PLCS Semantic Web applications • Makes PLCS Reference Data usable by non-PLCS applications • The STEP Systems Engineering community standard, ISO 10303-233, planning to adopt this approach and reuse PLCS Reference Data

15. Future use case: Automated planning Report to shipyard for engine maintenance Shore-based Maintenance Planning System Onboard Location Management System MPS distance = 16000km Ship data Onboard Location Management System distance = 8000km

16. Still looking for the “Killer” App or Demo Engineering Data Interoperability ISO 10303-25 Data Exchange/Integration Interoperability Region Software Modeling/Engineering Interoperability Region MDA,UML STEP, EXPRESS Concepts Properties Relationships OMG ODM OWL,CL ISO 15926? ISO ? OMG ODM? Semantic Integration and Knowledge Interoperability Region Harry Frisch

17. Sources of Reference Data • UK MoD, NATO and other standards • Codifications of tasks, skills, etc. • ISO 15926-2 Oil and Gas data warehouse projects (also called EPISTLE Core Model) • 4D ontology-based model submitted to IEEE Standard Upper Ontology Working Group, written in EXPRESS • Equipment types and some activity types (20K classes undergoing ISO standardization at the moment) • ISO 15926 community is investigating OWL as standard form of their reference data • Expecting 100K+ classes in multiple servers for full PLCS implementation

18. Issue : Ontology Management • This use case is not based in the “World Wild Web” • Ontologies are engineering artefacts used in complex systems • Some Ontologies are International and/or Industry Standards • Software “diff” for versioning not sufficient for this community • Protégé Server “anyone can change anything” not sufficient for this community • Change Management and Configuration Control of Ontologies (at least Class level) is required • This discipline is well understood in the engineering domain • Issues raised, proposals made, solutions approved, etc. • We lack Ontology tools for this at the moment and so are forced to use lots of separate OWL files and CVS – it’s not pretty

20. Issue : Ontology Subset or View • Using organizations contract for complex assets and software to manage them • The Reference Data required needs to be stated in the contract • Typical contract will not require all the Reference Data • Organizations need to specify a subset or view defining the Reference Data for the contract • Investigating Protégé PROMPT Plug-in but also investigating a Class-of-Class approach • Have tried to avoid Class of Class as then the RD is no longer DL

21. Pilots progress since the paper …

22. Web clients PLCS applications Define queries Define API As web services Implement OWL RDL Database Defined RDL content usingProtégé RD extensions (TBD) UK MoD RDL Server prototype

23. PLCS applications using the RDL Server: FMV model server • FMV Model Server is a STEP-based PLM capability for Web-enabled collaboration • Implements a significant portion of PLCS • Pilot project extended Model Server to use RD • Accesses RDL Server to allow dynamic classification of: • Activities, Parts, Documents • We could do this as Model Server is an extension of a Eurostep product called Share-A-space • Business benefits • Dynamically configurable PLM/PLCS application

24. When creating an Item, click green plus-sign to add new Classes from the RDL Server.

25. Select Classes from RDL Server to use in Model Server

26. The classes are now selectable in the listbox. Model Server has cached a copy. Choose one.

27. The Item is classified. Mouse-over Class and its definition appears. In a way, Model Server is allowed engineers to annotate their PLM data for SW

28. Typical RDL Web Service Query Query: What Classes are allowed when classifying an Identification assignment applied to a Product as realized? Restriction works for simple case, may need rules later (SWRL?) Answer: Serial identification code and Name. But not Activity identification code or Part number

29. Conclusion • The flexibility defined in the PLCS approach allows it to be used across a wide domain • However, that flexibility means PLCS implementation depends on Reference Data • OWL provides very good capabilities for defining, reusing, publishing and relating information models and reference data • By being Web-enabled, RDLs can be linked and distributed • OWL also enables the future use of knowledge/logic applications as part of PLCS implementations