CTS2 Specification

Discussion Notes

CTS2

Background• Lineage (LQS, CTS, LexEVS)• History (CTS2 SFM, RFP, HL7 Adoption process)• Current state– Feb 21 deadline– Mar OMG meeting– Jun OMG vote (ideally)

CTS2 Goals

• HL7 SFM Goals– CTS + distribution, “authoring”, versioning, value

sets and “post-coordinated expressions” (invoking reasoners)

• OMG RFP Goals– Fairly well aligned with SFM– Requires PIM + SOAP PSM

Additional Drivers and Requirements for Mayo

Additional drivers and requirements– Leverage NCI/Mayo LexEVS services– Leverage II4SM service model

• Quick initial implementations

– W3C / Ontology community buy-in– BioPortal compatibility– RESTful compatible PSM (and PIM…)– OMV alignment– Addl: Phin VADS, HL7 MIF, IHTSDO RF2

Approach

PIM – “Platform Independent Model”, mapped to multiple Platform Specific Models:

• REST PSM• SOAP PSM• iRDF PSM

PIM – combination of UML, text and Z

Challenges

What, exactly is a PIM?How do we create one model that aligns with

REST (our primary target), SOA(p), RDF minimalists and POJO?

No easy answers, but Z language seems to help considerably

Other Challenges

LexEVS – built, runs and already incorporates a significant portion of what is in the requirements

• LexEVS (XML / POJO) to PIM is a non-trivial transformation

• Reproducible behavior is a non-trivial processDecision was made to build CTS2

implementation using LexEVS vs deeper embedding.

Before we get started

Specification approachUML / text / Z• (At the moment, Z is most current)• Text and UML follow (or not) at varying rates

Do I need to know Z to read it?– At the moment, it would help a lot but…– … the intent is that the text faithfully, clearly and

accurately reflects what is said in the Z

Other details

Z means LaTeX (more or less) • Your faithful narrator is not a LaTeX expert,

meaning that it tends to be odd, clumsy, etc.• … any assistance would be greatly appreciatedBrowsing and authoring access is available

online (!)• Anyone w/ a logon can update and regenerate

sections of the spec

Current Status

Working through Code System / Code System Version trying to complete import/export/updates/version and query modelNot as far as we’d hoped to be, but are learning a lot.

Working w/ Dr. Davies / Oxford to improve Z style, readability, and contentChanges coming and (unfortunately) partially reflected in

model today.

UML model is considerably behind the curve at the moment… thanks to a certain UML vendors new-found obsession with security.

Outline of the Specification

1) (Quick intro to working directories)2) (Quick intro to web site)

Outline of the Specification

CoreData Types• Complete and independent for various PSM

mappings• As minimum as possible• Eschew Boolean• Review TypesOfURI (and why “U”)• Review EntityReference (the foundation of the

model)

Outline of the Specification(continued)

CoreNamingRDFTypes – the link to the W3C worldUpdates• The core of the workflow, revision and version

model.

Outline of the Specification(continued)

CoreResources• Resource Description model– Include what resources we describe

• ARD / RVD – what and why• Also focus on the RESTful notion of “Resource”

“Resources”

In this context, a “resource” refers to one of the fundamental components that are represented in a CTS2 service. The CTS2 specification states how these various “resources” are represented, queried and updated.

Flavors of Resource

Abstract ResourceCode SystemMappingValue SetConcept Domain

Resource VersionCode System VersionMapping VersionValue Set DefinitionConcept Domain Binding

Outline of the Specification(continued)

CoreStatements• Serves 3 purposes:

1) Link between structured (UML) model and RDF triple-based model

2) Point of extensibility (describe)3) Anchor point of “association”

Outline of the Specification(continued)

CoreIteration and Filters• Generic query structure – by model element

or statement• Directory model (read only resources)

Outline of the Specification(continued)

Information ModelCode System (aka. Ontology)Code System Version (aka. Ontology)Value SetValue Set DefinitionValue Set Resolution RuleMappingMapping VersionConcept Domain (aka Data Element Concept)Concept Domain Binding (aka Data Element)

Outline of the Specification(continued)

Information ModelAnd …• Entity – the core aspect being represented– Subdivisions to Class / Individual / Role– Reasons that Entity is not abstract (valid?)

Brief Interlude on Complaince

Code System (Version), Value Set (Definition), Concept Domain (Bindings), Mapping (Version) and Entity are all independent compliance points (!) (dependencies present interesting problems)

Query / Loader / Exporter / Authoring / History services are all compliance points as well

Additional extension (compliance) points wrt. Statements, SPARQL, Context Matching, Event Notification, Business Rules (?) and Loading

Reasoning Services

• (go over II4SM and SFM)