a view into services architecture in healthcare

04/21/23 09:18

EDS and the EDS logo are registered trademarks of Electronic Data Systems EDS and the EDS logo are registered trademarks of Electronic Data Systems Corporation. EDS is an equal opportunity employer and values the diversity ofCorporation. EDS is an equal opportunity employer and values the diversity ofits people. © 2004 Electronic Data Systems Corporation. All rights reserved. its people. © 2004 Electronic Data Systems Corporation. All rights reserved.

A View into Services Architecture in HealthcareA View into Services Architecture in Healthcare

Kenneth S. RubinEnterprise Architect, EDS

[email protected]

Kenneth S. RubinEnterprise Architect, EDS

[email protected]

© 2004 Electronic Data Systems Corporation. All rights reserved. © 2004 Electronic Data Systems Corporation. All rights reserved.

Presentation OverviewPresentation Overview

• Common Services: A Reference Model

• Common Services within VHA

• HL7.org and Common Services


Common Services: A Reference ModelCommon Services: A Reference ModelCommon Services: A Reference ModelCommon Services: A Reference Model


Why common services?*Why common services?*

• A common practice in healthcare, just not yet in healthcare IT

• Many key products use them but do not expose interfaces

• Ensures functional consistency across applications

• Accepted industry best practice

• Furthers authoritative sources of data

• Minimizes duplication across applications, reuse

*slide adapted from 2004 ITC Presentation on VHA Common Services


ISO Layers: Sufficient?ISO Layers: Sufficient?

Application

Presentation

Session

Transport

Network

Data Link

Physical Platform


ISO Layers: Insufficient!ISO Layers: Insufficient!

Application

Presentation

Session

Transport

Network

Data Link

Physical Platform

Middleware, Static-binding, Stds BasedCustom/Proprietary Interfaces

Dynamic (Extensible) SemanticsStatic (closed community) Semantics

Middleware, Dynamic-Discovery, Stds Based

Dynamic (Extensible) Stds-based Semantics


Pyramid of InteroperabilityPyramid of Interoperability

Ab

ilit

y to

Int

erop

erat

e

High

Low


Scaling the Pyramid: ExamplesScaling the Pyramid: Examples


Common Services within the Common Services within the Veterans Health Administration (VHA)Veterans Health Administration (VHA)Common Services within the Common Services within the Veterans Health Administration (VHA)Veterans Health Administration (VHA)


First, a little about VHA* First, a little about VHA*

• Business View– 158 hospitals/medical centers

– 854 outpatient clinics

– 132 long-term care facilities

– 42 rehabilitation facilities

– Affiliated with 107 of 125 medical schools in the US

• Healthcare Statistics (2003)– 7.2M beneficiaries enrolled

– 4.8M treated

– 49.8M outpatient visits

• Operational View– 180k VHA employees

– 13k physicians, 49k nurses

– 85k health professionals trained annually

– USD $29.1B Budget for 2004

• Technical View– VistA (EHR) for over 20 years

– Software portfolio exceeds 140 applications

– Reengineering effort is based upon a services architecture

*statistics taken from May 2004 Fact Sheet, U.S. Dept of Veterans Affairs


Relevant ContextRelevant Context

• VHA is among several (U.S.) Federal healthcare organizations (DoD, IHS, HHS, CDC, FDA to name a few)

• National Coordinator for Health IT has been appointed

– US NHII – Public/Private involving regional and local pilots

– Four focus areas:

• Bring technology to points of care • Interconnect clinics

• Patients as informed • Support population health consumers

• Approach is for government to lead and not mandate

• VHA has related efforts to address information semantics


VHA’s Service Architecture ObjectivesVHA’s Service Architecture Objectives

• Minimize duplication and inconsistency of implementation

• Position VHA to support significant platform changes, isolate from middleware technology

• Allow for flexible deployment approaches without changing client applications

• Support multiple concurrent middleware technologies

• Facilitate integration with external systems, off-the-shelf products

• Minimize maintenance burden

• Establish services as authoritative sources of data

= implied objective

= stated objective


VHA’s Road to Service ArchitectureVHA’s Road to Service Architecture

HealtheVet VistAPlanning

Web Apps.

PatientLookup,PatientService Hardware design, procurement and deployment

PersonDemographics

NEW PERSONenumeration

HDRprototype

StandardData

Service

CAIP

Delivery Service

Systemsof

Interest Naming /DirectoryService

MessagingService

HL7 BuilderUtility

PersonLookup

Data standardization

DataCleanup

Dynamic Routing Service

Data Aggregation & Migration

Site Preparation & Training

Re-hosting of VistA Applications

Removal of M systems

Performance Tuning

Person Identity Management


VHA Service Architecture: Conceptual view VHA Service Architecture: Conceptual view

Panel One: CAIP Concept Architecture

MiddlewareMiddleware

Virtual Enterprise Services Boundary

MPIService 2HDRService 1

Application nApplication n

If Necessary

Application 2Application 2


Capabilities

Technology–Specific Invocation Incoming Invocation

(Technology

Components

Business

TechnologyAdapters

Component

Proxy

MiddlewareMiddleware

Virtual Enterprise Services Boundary

MPIService 2HDRService 1

Application nApplication n

If Necessary



CAIP Invocation(Interface Signature)

Capabilities

Technology–Specific Invocation Incoming Invocation

(TechnologySpecific)

BusinessDelegates

TechnologyAdapters

Component

ServiceFacade


VHA Lessons Learned with Common ServicesVHA Lessons Learned with Common Services

• Alternative Triple-constraint: idealism , practicality, timeliness

• Establish agreed-upon architectural principles

• Need for architectural vision to integrate with project teams

• Need for a solid migration strategy (technology and staff)

– Don’t overlook cultural maturation issues

– Sequence planning is essential

– Managing organizational trust

• Need to differentiate “infrastructure” from “business” services

• All-compassing requirements management


Services Architecture within HL7.orgServices Architecture within HL7.orgServices Architecture within HL7.orgServices Architecture within HL7.org


HL7: The Services “Climate” TodayHL7: The Services “Climate” Today

• HL7 has several service-oriented efforts (CCOW, CTS, Java, ITS)

• Each has considered itself outside the mainstream of HL7 Activities

• The methodology and approach to each effort has been “unique”

• Informal “Services Birds-of-a-Feather” community has maintained steady interest

• Most of HL7 remains message focused


Emerging AreasEmerging Areas

• MDF to HDF transformation

– More than messaging

– Support for multiple ITS specifications

– More rigorous alignment to UML

• Tooling Task Force

– Off-the-shelf

– Requirements-driven, organizational priorities

• HL7 Organization Review Committee


What about the Services BOF…What about the Services BOF…

• “Why isn’t it a formal committee?”

• Informal group meeting for several years

• Regular meetings with average of 20 attendees

• Offered formal sponsorship under EHR TC

• Possibility of “Going SIG”


The climate is changing… The climate is changing…

• The HL7 HDF nears deployment

• Interest and sponsorship by EHR TC

– HL7 EHR Functional Standard adopted May 2004

– EHR TC sees services as the next step

• HL7 is responding to national interests

– HL7 Canada, HL7 UK, HL7 Australia exploring solutions involving services

– US NHII initiative appears to be influencing the HL7 Board of Directors

• Joint meetings with OMG have begun


What needs to be done…What needs to be done…

• HL7 International Affiliates continue to push, inform HL7 Board of the importance and interest in services

• Services BOF must be either chartered as a committee or (preferably) incorporated in the HDF

• Support and promote HL7 partnership with SDOs focused in the services space

• HL7 should recognize the strengths and weaknesses of its membership volunteers


ReferencesReferences

• VHA Website:

• http://www.va.gov

• VHA HIA Website:

• http://www.va.gov/vha-ita/ita-p.html

• HL7 Website:

• http://www.hl7.org

• NHII Information:

• www.hhs.gov/onchit/


Acknowledgements and Thanks To…Acknowledgements and Thanks To…

• VHA Health Information Architecture Office

• VHA Common Services Team (for their review of this presentation for technical accuracy, and permissions to use and adapt several of their presentation slides)

• PlugIT, the University of Kuopio, and HL7 Finland (for the opportunity and sponsorship)

• Juha Mykkanen

• Mikko Korpela

04/21/23 09:18

EDS and the EDS logo are registered trademarks of Electronic Data Systems EDS and the EDS logo are registered trademarks of Electronic Data Systems Corporation. EDS is an equal opportunity employer and values the diversity ofCorporation. EDS is an equal opportunity employer and values the diversity ofits people. © 2004 Electronic Data Systems Corporation. All rights reserved. its people. © 2004 Electronic Data Systems Corporation. All rights reserved.

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