Ontology in Model-Based Systems Engineering
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Transcript of Ontology in Model-Based Systems Engineering
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USA
Ontology in Model-Based Systems Engineering
Henson Graves29 January 2011
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USAPreview Of Monday Discussion Topics
• SysML and ontology in biomedical modeling• Ontology reuse in MBSE• Ontology for identifying and resolving model
ambiguity • Approaches to integrating SysML with logic
based frameworks, e.g., OWL• Overlap with other MBSE working groups
– Enterprise modeling (DoDAF, …– MBSE standards
• Issues, questions, what else is going on,…
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USA
SysML and Ontology in Biomedical Modeling
Henson Graves
Yvonne Bijan30 January 2011
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USAHuman Heart Use Case For Structural
Modeling
Focus of conceptual modeling is on structure
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USAConceptual Modeling Objectives
• Construct a model that captures what is common to all (or at least) most human hearts
– corresponds to product model, or product line
• Perform general reasoning about effects of pathology and disease symptom propagation
– general properties of operation
• Use general case to analyze and reason about a specific heart
– fault detection
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USAMBSE Interest
• Do the modeling principles used by Description Logic (OWL) community offer anything for MBSE?
• Will these examples and the DL models help us understand how to integrate formal reasoning with SysML?
• How do biomedical examples look in SysML?• Do the modeling principles used for air
vehicles and other systems work in biomedical domain?
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USA
Ontology Reuse In MBSE
Henson GravesJanuary 2011
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USAOntology Applications in MBSE
• Examples – Units and measures– Physical interactions (laws)– Material classification and properties– Enterprise concepts
• Levels of rigor– Vocabulary – Informal textual semantics of vocabulary– Formal (axiomatic) semantics
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USAExample Opportunity: Analysis Result
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USAApproaches To Achieving Ontology
Reuse
• Identify candidate ontologies, acquire and make available
• Start over with uniform modeling principles
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USA
Common MBSE Modeling Questions and How Ontology Helps
Henson GravesConrad Bock
January 10, 2011
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USAWhat Does a Model Describe
• Are the things described by a model all the same, or can they be different?– In particular, do they all have the same parts linked together
in the same way?
• The answer is no (perhaps intentionally) if– The model is incomplete.
• Does a car have more than engines and wheels?– Are there any specializations of the model? Is there more than one
model of the same car?
– The model is complete, but isn’t specific.• What kind of engine? What kind of wheel? Which goes with
which?– Parts aren’t distinguished or equated.
• Does the car roll on the driven wheels?
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USAOntology Languages
• Ontology languages enable modelers to say how they want these questions to be answered
• Doesn’t mean system engineers need to learn ontology languages– Ontology languages can motivate and validate extensions to
SysML/UML and other modeling languages to address ambiguities
• Improves quality of communication between people, between people and machines, and between machines– Giving a model a descriptive name (“complete car model”)
does not mean that people or machines know exactly what you are talking about.
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USA
Integrating SysML with OWL
(or other logic based formalisms)
Henson Graves Conrad Bock
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USAWhy Integrate SysML With Logic
• Engineering has always been about • building models of real world domains,
– analyzing models and making measurements
– refining and modifying the models
• Integrating a modeling language with logic-based system enables
– Standardization of model semantics
– Checking that model integration does not lead to inconsistency
– Automated reasoning tools to perform tasks which outstrip manual capability
– formal derivations for justification of engineering decisions
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USAHow Does Integration With Logic
Achieve Objectives
• Constructions in logical language are given (axiomatic and/or referential) semantics, e.g.,
– Codify expected properties of language constructions such as subclass, instance, part,…
– Allow users as they model systems to not be dependent on subject matter experts to convey their meaning
– Use automated reasoning, based on formal semantics, for consistency checking as models are developed and merged
– Formal derivations (proofs) can provide justification for assumptions and decisions made on basis of models
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USASome Different Approaches To
Integration
• Learn some logic based language, say FOL, or OWL and use that
– recognizing that logic is primary
• Translate SysML into OWL and back in so far as is possible
– Switch back and forth
• Provide SysML with a formal logical foundation
– allow users to work within SysML and take advantage of reasoning tools
International Workshop28 Jan – 2 Feb 2011
Phoenix, AZ, USA
A Stack of Semantic Standards for Ontologies
To enable semantic interoperability
Increasing use of standards
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Resource Identification Standards
Data Interchange Format Standards
Metadata Standards
Modeling Language Standards
OntologyStandards
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