Transcript Applying Semantic Web Technology to the Life Cycle Support

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Applying Semantic Web Technology to
the Life Cycle Support of Complex
Engineering Assets
David Price and Rob Bodington
[email protected]
ISWC 2004
Agenda
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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
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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, AsMaintained
– 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
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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, …
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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
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PLCS Requirements
ISO Information Model
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OASIS Reference Data
Basic PLCS Implementation Scenario
translate
to PLCS
translate
from PLCS
XML exchange
document
HUMS
MM
S
classification
Health and Usage
Monitoring System
on board a ship
Maintenance
Management
System
Linked Reference Data
Libraries
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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
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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
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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
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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
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PLCS Ontologies When Deployed
classification
Reference Data for
Organization
Editors
XML exchange
document
MoD-rdl-extensions
import
subClassOf
Reference Data for
PLCS Users
(read-only)
plcs-rdl
Reference Data for
PLCS Editors
plcs-refdata
subClassOf
plcs-express
Dublin Core
Elements and
Terms
(read-only)
plcs-dc
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plcs-dcterms
PLCS EXPRESS
as OWL
(read-only)
The EXPRESS/RD OWL Relation
PLCS Schema
Classes
RD Classes
subClassOf
PLCS Schema
Classes
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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 10303233, planning to adopt this approach and reuse PLCS Reference
Data
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Future use case: Automated planning
Report to shipyard
for engine maintenance
Shore-based Maintenance
Planning System
Onboard Location
Management System
distance = 16000km
MPS
Ship data
Onboard Location
Management System
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distance = 8000km
Engineering Data Interoperability
Still looking for the “Killer” App or Demo
ISO 10303-25
Data Exchange/Integration
Software Modeling/Engineering
Interoperability Region
Interoperability Region
STEP,
EXPRESS
Concepts
Properties
Relationships
MDA
,UML
OMG ODM
OWL,CL
ISO 15926? Semantic Integration and Knowledge
ISO ?
Interoperability Region
OMG ODM? ®
Harry Frisch
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
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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
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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
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Pilots progress since the paper …
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UK MoD RDL Server prototype
Web clients
PLCS applications
PLCS Clients
FMV
Model Server
Define queries
Define API
As web services
Implement OWL
RDL Database
Defined RDL
content using
Protégé
RDL Class
browser
AP233
Demo
Web
browser
TCP/IP --- LAN / Internet backbone
OWL API
Web
services
OWL XML
Queries
Web
server
MySQL
Database
PLCS RDL Web Server
OWL API
Web
services
OWL XML
Queries
Web
server
MySQL
Database
MOD RDL Web Server
RD extensions (TBD)
Protégé
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OWL files
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
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When creating an Item,
click green plus-sign to
add new Classes from
the RDL Server.
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Select Classes from
RDL Server to use in
Model Server
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The classes are now
selectable in the listbox.
Model Server has cached a
copy.
Choose one.
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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
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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?)
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Answer: Serial
identification code
and Name. But not
Activity identification
code or Part number
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
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