the epistle reference data library an ontology for the process industry

http://www.scadaonweb.com

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


Thermowell stem


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

the epistle reference data library an ontology for the process industry

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