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THE HARMONIZED MODEL
John R. Herring
Convener
Harmonized Model Maintenance Group
History of Western Philosophy
Bertrand Russell, 1946
One of the defects of all philosophers
since Plato is that their inquiries …
proceed on the assumption that they
already know the conclusion to be
reached.
References
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Text (avoid “cookbooks”- too application specific)
 The Unified Modeling Language Reference Manual
— James Rumbaugh, Ivar Jacobson, Grady Booch
— Addison-Wesley (2nd edition, 2005)
Specifications www.omg.org, www.opengeospatial.org
 OMG Unified Modeling Language (OMG UML),
Infrastructure
 OMG Unified Modeling Language (OMG UML),
Superstructure
 OGC 08-131r3 The Specification Model — A
Standard for Modular specifications
Purpose of the Harmonized Model



Harmonize ISO TC 211 standards
http://www.isotc211.org/pow_all.htm
Define a common object-oriented vocabulary
Provide a common basis for implementations
 INSPIRE
http://inspire.jrc.ec.europa.eu
 SEE Grid (solid earth environment grid)

Two inherent logical layers:
 Conceptual
– root of interoperability
 Implementation – root of plug-n-play
HMMG Home —
http://www.isotc211.org/hmmg/HTML/root.html
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Links to –
 Model data download
 Dependency document.
 An HTML view of the Harmonized Model
 Publicly readable “subversion” repository
from CSIRO’s SEE Grid web site.
 Version
of all parts, standards and work in progress.
 Refreshed multiple times daily.
What the Harmonized Model is
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


A UML model defined (in pieces) by the official
editions of ‘every’ ISO TC 211 standard
Through various human errors, there are some
problems.
The HMMG has only limited authority to fix these
 The


Model shall match the documents
Minor fixes are done to align the model with the
documents
Other problems are referred to “leads” and may
result in corrigendum or other fixes.
UML in the HM
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

See Reference Manual cited
Is not a graphics editor
 Is
a set of formal graphics languages with wellspecified meanings and interpretations

Can be some of many things:
 Ontology,
object design, resource design (REST),
process design, system architecture

Well governed system; rules of use, flexible but
strict
 Layers
of model and metamodel, abstractions: ’09, ’10
 Compliance can be loose or tight: ’07, ‘36
Model procedures with repository
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



Edited with Enterprise Architect in (a local copy of)
the Harmonized Model (to track GUIDs) – always!
Stored in a “subversion” repository at JRC.
Stored as XMI, each document, published edition –
linkages by GUID, not names which may change
Management is done by EA and Subversion
 New
EA commands: check-out, check-in, refresh (often)
 By document editor, or HMMG approved staff

Repository can “recover” the state after any
transaction, from any date, state of model
Basic procedure with repositories
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Repository
Check-out
Local Copy
Edit
…
Transaction
Repository
Edit
Check-in
Local Copy
Model procedure using copies
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




Editor begins with a new copy of the harmonized
model
New package is created for each document/edition
Editor periodically (monthly?) posts his documents
model to the HMMG
HMMG does a quick merge, update and post
Editor retrieves new copy of his doc in HM (all other
documents are refreshed to current state)
Some limitations
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




Nothing changes unless the package is checked out
before and checked in after (commits a transaction)
An editor should only check out his document
Elements in XMI are identified and linked only by
GUIDs, globally unique identifiers
GUIDs enable round tripping of the XMI at any
granularity (one package to whole model)
Multiple versions of same document mean no name
uniqueness (especially within a series)– all linkages
are by GUID
The Future — Direct repository use
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



Currently editions are posted through the HMMG
leads, editors work in copies of the model
In the future, editors will access their own documents
in the repository – transactions through local copies
The repository procedures will keep them from
changing anything they do not own
Subversion tracks all changes, records all states and
which user does what.
Known Issues (under work / debate)
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
Unit of reuse (OGC ‘Modular specification policy’)
 Unit
of reuse in a standard is the conformance class
 Unit of reuse in a UML model is the package
 In the future, UML packages in the harmonized model
should respect conformance class boundaries

Direct Access to repository by editors
 Plans
to create an “partially editable mirror”
 Working documents editable by PT/EC
 Published documents read-only (maintained by HMMG,
strict consistency rules – tagged for development
processes)
Questions?
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cover of New Yorker; August 4, 1986