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Ontology Reuse In MBSE

Henson GravesJanuary 2011

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Outline

Examples of reuse of existing ontologies

Potential reuse Opportunities

What are the benefits

Approaches to ontology reuse

Some observations on reuse

Next steps

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Ontology Reuse In MBSE

Examples Units and measures Physical interactions (laws) Material classification and properties Enterprise concepts

Levels of rigor in ontologies Vocabulary Informal textual semantics of vocabulary Formal (axiomatic) semantics

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Potential Reuse Opportunities

Analysis Process Occurrence- activity that takes place at some specific time, place, etc.

External Structural Loads

(Region)

isResultOf

hasValue

Analysis ResultappliesTo: External Structural

Loads of A1 Air FrameusesMethod: CFD

with parameters: surface, mass properties, and maneuver spectrum

isProducedByTask:isRequiredForEvent:

Satisfies

CFD Method

usesMethod

Air Vehicle

AnalysisSetupsatisfiesDescriptionisResultOf

TimePlaceEquipment

hasValue

Measures

appliesTo

hasValue

Ontology for system engineering artifacts

Ontology for product structure and attributes

Ontology for measurement value spaces

Ontology for computational methods

Ontology for experimental setups

Ontology for events

National Aeronautics and Space Administration

Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadena, California

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Ontologies may be Organized into hierarchies

Foundation Ontologies

Base, Mission, Project,Quantities-Units-Dimensions-Values,

Analysis, Artifact, Architecture Description

Discipline Ontologies

Mechanical, Electrical, Physics, Thermal,

Propulsion, Attitude Control, Navigation, …

Application Ontologies

Star Tracker, Sun Sensor, Reaction Wheel, Thruster,..

2-axis vs. 3-axis S/C; Radio vs. optical comm; …

use

use

use

Fundamental terms use in all projects, disciplines, and applications

Discipline-specific terms specified and owned by discipline experts

Kinds of items that are modeled in a project; specified and owned by application experts

Focus is integration and interoperation

Focus is reuse

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What Are The Benefits

Leveraging reusable knowledge to jump start engineering

Basis for model integration and large scale collaboration

Standardization of engineering work products

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Approaches To Achieving Reuse

1. Opportunistic Reuse: identify candidate ontologies, acquire and refurbish and make available

2. Designed Reuse: establish modeling principles and start over, making use of lessons learned

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Opportunistic Reuse

Identify candidate ontologies, acquire and refurbish and make available

Opportunistic reuse has only had limited success in Hardware component design Software design

Reuse only worked well when the right units of modularization were understood, e.g. ASICS, Patterns

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Designed Reuse Process

Collect any reuse ontology candidates

Document modeling principles to be used in redo

Chose a foundation (upper) ontology, e.g., DOLCE in accord with design principles Modify if needed, based on experience

Create specializations of subsets of the upper ontology, e.g., For physical laws, enterprise concepts

Repeat as needed

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Upper Ontology Concepts That Might Be Useful

Classes Properties

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Example From Upper Ontologies That Is Particularly Useful: Qualities

Physical Object

QualityType

MeasuredWeight

1D SpaceWith units

Empty 1969 VW

Car

Weight object

hasMeasuredWeight

hasQuality

inPounds

18K pounds

<Vw,mwt> <mwt, 18k>

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Next Steps For Ontology Reuse Development

Get a working group established for this purpose

Collect any reuse ontology candidates

Document modeling principles to be used