The EPISTLE Reference Data Library an ontology for the Process Industry
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Transcript of The EPISTLE Reference Data Library an ontology for the Process Industry
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The EPISTLE Reference Data Library
an ontology for the Process Industry
David Leal, CAESAR Systems Limited
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EPISTLE - major sponsors and members
EPISTLE
PISTEP 2000(UK)
BNFL bp Conoco Foster Wheeler
Energy Shell
POSC Caesar(Norway)
Cadcentre Det Norske
Veritas FMC Kongsberg
Subsea Intergraph Norsk Hydro Statoil
USPI-NL(The Netherlands)
ABB Akzo Nobel Fluor Daniel NAM Shell
EPISTLE: European Process Industry STEP Technical Liaison Executive
STEP : STandard for the Exchange of Product data (ISO 10303)
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What sort of thing is it?
MANUFACTURERS DRAWING
32 30 STUDBOLTS 1”UNC, 5 1/ 2 ” ASTM A453 GR660 EN10204/2.264 31 NUTS 1”UNC ASTM A453 GR660 EN10204/2.2
2 29 SUPPORT BRACKET 6-194-4
ENGINEERING DATASHEET
07.1 Bolts/External Flnges ASTM A 453M GR660, TP1 (3.1B)
07.1 Nuts External Flanges ASTM A 453M GR660, TP1 (3.1B)
07.1 Brackets/Supports BS 1501-316-S11__________ (3.1.B)
ASTM A 453/A 453M - 660 CLASS A
ISO 15926 REFERENCE DATA LIBRARY
Need one place to store the meaning and map between different terminology
Acknowledgements to Acknowledgements to POSC/CAESARPOSC/CAESAR
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Our starting point
STEP - ISO 10303 STandard for the Exchange of Product data shape FEA (Finite Element Analysis) PDM (Product Data Management) special models forshipbuilding, plant spatial layout, electrical
design engineering semantics - what things or relationships are real world vs designs/classes/specifications
Parts Libraries - ISO 13584 families of standard parts a methodology for unique part identification some use of set theory
?
Complicated, ad-hoc information models - result of a learning process
begun in1984
not web
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ISO 15926
Life cycle data for process plants including floating, flying, and with wheels simple basic model extended by class libraries (i.e. ontologies)
STEP technology - EXPRESS Entity/Relationship language - similar to UML (static class diagram) simple exchange file representation API - bindings to C, C++, Java XML representation - horrible
Consequences hard wired information model - voted on by ISO, and not easily
extensible extension by standard instances held in external files (class
libraries) - also standardised by ISO - externally maintained registry with continuous revision ERDL
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A thermowellAcknowledgements to Acknowledgements to
POSC/CAESARPOSC/CAESAR
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Thermowell (Dry Well) POC (01.01.08)
Functional Parts
Physical Parts
Subclasses
Properties
Thermowell Estimated Dry Weight
Measured Dry Weight
Thermowell stem
Thermowell Process Connection
Internal thread
Thermowell Instrument Connection
Thermowell insertion length
Thermowell standout length
Thermowell lag length
Thermowell total length
Thermowell internal bore
Welded(Weld-in)
Thermowell
FlangedThermowell
ScrewedThermowell
Van StoneThermowell
Tapered Stem
Thermowell
SteppedStem
Thermowell
Socket WeldThermowell
Welded FlangeThermowell
Solid ForgedFlanged
Thermowell
Straight Stem
Thermowell
NORSOKI-001 Rev. 3 T01
Thermowell
ISAS20T2501
Thermowell
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Thermowell Stem (Dry Well) POC (01.01.08)
Physical Wholes
Properties
Properties
Subclasses
Thermowell stem largeroutside diameter
Thermowell stem tipoutside diameter
Upper limit thermowell stemoutside diameter
Thermowell stem tip thickness
Thermowell
NORSOKI-001 Rev. 3 T01
Thermowell stem
NORSOKI-001 Rev. 3 T01
Thermowell
Thermowell internal bore
Wake / natural frequency ratio
ISAS20T2501
Thermowell Stem
ISAS20T2501
Thermowell
Thermowell stem outsidediameter at support
Thermowell Stem
TaperedThermowell
Stem
SteppedThermowell
Stem
StraightThermowell
Stem
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Part type and materials
crankshaft
V6 crankshaft
Rover 75 crankshaft
Rover 75 crankshaft rev1.2
rotating part
engine part
machined-surface part
unmachined-surface part
part with oil holes
cast iron
SG cast iron crankshaft
SG cast iron
SG cast iron grade XYZ
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ECM and ERDL (ISO 15926) Structure
ConceptualEngineering Design
ConceptualProcess Design
DetailedProcess Design
Detailed Engineering Design
Procurement
Construction
Commissioning
Maintenance
Property Classes
Activity C
lasses
Standardised in ISO 15926-2
Basic concepts
Product catalogsrepresented using ISO 15926
Commodity Classes
Manufactured Item Classes
Standardised by e.g. ISO /IEC/ ANSI/ BS/DIN,represented using ISO 15926
Standard Classes Physical Object C
lasses
Common terminologyCoreClasses
Standardised in ISO 15926-4 WD
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ERDL - size of the problem
basic concepts ~ 200
core classes ~2000
first release of standard classes ~ 20000 - more to come
commodity classes ~ 1 million for big owner-operator
manufactured items ~ ?
product/artifact, activity, state, composition, connection
thermowell, pump, pipe, flange, raised face flange
ISAS20T2501 thermowell
A design/specification is a class.
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ERDL - how to define the classes
basic concepts ~ 200
core classes ~2000
first release of standard classes ~ 20000
commodity classes ~ 1 million for big owner-operator
manufactured items ~ ?
information modellers - theoreticians with an industry background
teams of domain experts - initial tutorials from the information modellersheat transfer team, piping team, rotating equipment team, etc.
further work by domain expertsconversion of existing standards - using standard procedures
uptake of methodology by industry
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dictionary
Key concepts
product/artefact
product life segment/activity
product at instant/state
A distribution of matter through space and time, that is regarded as the whole life of an object by some business process
A product for a particular period of time.
A product at an instant in time.
start with real world things:
then sets/classes of real world things;
then classes of class, etc.
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ERDL Scope
piping valves rotating equipment heat exchangers electrical machinery electrical distribution instruments connections activities (for plant design, operation, maintenance) civil/structural documents (for plant design, operation, maintenance) properties (for classes defined above) units
core classes in each area
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Some experiences
keep the hierarchy flat - without two many intermediate layer not a strict hierarchy, but a directed graph intermediate abstractions are 'woolly' people argue about them endlessly
product
rotating equipment
pump expander
Is this really needed?Does it have a precise definition?
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Use of classification of class
Makes 'woolly' classes less visible but still there - power set
product
pump expander
rotating equipment class
indicates the responsible team of domain experts
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Use of classification of class
Filtering for drill down
product
thermowell
instrument class
generic class
ISAS20T2501
instrument class
standard class
ISA class
J. Bloggs model XYZ
manufacturer class
J. Bloggs class
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Rules for the development of class libraries
Stick to classes with precise definitions write the text definitions as you go
Do not add 'collector' classes to structure the class library
Use classification of class to provide structure Some classes can be defined by set theory and property
contraints. It is not practical to do this for all classes. Text definition of the form:
'A xxx is a <superclass of xxx> that
<distinction between xxx and its superclass>.'
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Intersection of classes
cast part
engine part
cast enginepart
A complete definition of 'cast engine part' without words!
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Intersection of classes
cast part
engine part
Two subset relationships are not a complete definition!
cylinderblock
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core model
Class hierarchy
thing
physical object
‘product’ / artefactproduct
for a period of timeproduct
at an instant in time
thermowell
flanged thermowell screwed thermowell welded thermowell
the one in my plant is one of these
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Recording real world objects
The part with serial number 98/1234 is an instance of screwed thermowell
The part with serial number 98/1234 is an instance of product, classified as a screwed thermowell
<ScrewedThermowell><label>98/1234</label>
</ScrewedThermowell>
<Product><type resource=“#ScrewedThermowell”/> <label>98/1234</label>
</Product>XML equivalent t
o the
EXPRESS implem
entatio
n
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core model
Dictionary
thing
class ofphysical object
class of‘product’ / artefact
class of productfor a period of time
class of productat an instant in time
class
thermowell is one of these
screwed thermowell is one of these
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Recording classes
Screwed thermowell is an instance of class of product
Relationship to the class ‘Product’ is implicit.
<ClassOfProduct ID=“ScrewedThermowell><label>Screwed thermowell</label><subClassOf resource=“#Thermowell”/>
</ClassOfProduct>
<ClassOfProduct ID=“Thermowell”><label>Thermowell</label><subClassOf resource=“#Product”/>
</ClassOfProduct>XML equivalent t
o the
EXPRESS implem
entatio
n
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Relationships and constraints
ISA S20T2501T
ISA S20T2501TS1 part
1 whole
ISA S20T2501 stemstemcompositioncomposition
• Each ‘ISA S20T2501T’ Thermowell has one ‘ISA S20T2501TS’ Thermowell stem as a part.
thermowellthermowell
thermowell stemthermowell stem1 part
1 whole
thermowell stemthermowell stemcompositioncomposition
• Each thermowell has one thermowell stem as a part.
productproduct compositioncomposition
* part
* whole
• Each product has zero, one or many products as parts.
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Individual and class models
productproduct compositioncomposition
* part
* whole
class of productclass of product class of compositionclass of composition
* part
* whole
my_thermowellmy_thermowell_stem
my_thermowell_stem is part of my_thermowell
thermowellthermowell_stem
thermowell_stem is part of thermowell
allowed cardinality
classification
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ScadaOnWeb
variables
positionsstates/times
semantics
gigabytes of structured
data
extract and download subsets
Define semantics of process monitoring data with respect to web ontologies
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Next steps for EPISTLE Exploit the current standards
EXPRESS tools are mature, and scalable (but expensive)
But Ontologies need publication and management Why develop EXPRESS based tools for ontology publication and
management, when there is a much bigger community out there
Currently class libraries held as files corresponding to the ISO 15926
EXPRESS schema tools support import/export from a simple EXCEL spreadsheet class library development uses EXCEL
Future domain class libraries published as an ontology on the web retain use of EXCEL by domain experts ISO 15926 basic concepts as a web ontology
?
WonderWebScadaOnWeb
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Conclusions
Large body of work - searching for a formal representation on the web
Generic tools needed for access and maintenance merging libraries are particular problem
Multi-layer structure need a consistent format for all levels no sharp distinction between data and meta-data (a design is a
class)
www.epistle.wswww.epistle.wswww.posccaesar.orgwww.posccaesar.org
www.uspi.nlwww.uspi.nlfor more informationfor more information