International Journal of Medical Informatics 48 (1998) 137–143

The Andover Working Group—accelerating the implementationof standards

Jack Harrington *, Chris Melo, Geoff Pascoe, Dan Trainor

Hewlett Packard, Medical Products Group, 3000 Minuteman Road, Ando6er, MA 01810, USA

Abstract

The Andover Working Group was formed with the objective to accelerate and broadly deliver standards-basedsolutions for healthcare which feature plug and play interoperability across the continuum of care. In this paper,organization and processes used by the Andover Working Group are discussed. A description of how multilateralmessage profiles, combined with object-oriented component middleware supporting application developments,systems integration and systems operation remove many of the barriers to deployment of systems of standards basedapplications is also given. © 1998 Elsevier Science Ireland Ltd. All rights reserved.

Keywords: Standards based applications; Multilateral messages; Object-orientated component middleware

1. Introduction

Whether the results of a ‘best of breed’architecture, the consolidation of formerlyindependent organizations, or of governmentmandates for electronic communication ofhealthcare information, heterogeneity is afact of life in today’s healthcare enterprise.Driven by an accelerating re-engineering ofthe healthcare delivery process, integration ofsystems in a heterogeneous environment isone of the top priorities of executives respon-

sible for healthcare information technology[1].

There is a general agreement that openstandards are a key component in solving theproblem of integration of systems in a hetero-geneous environment. Internationally, thechallenge of developing the standards neededhas been taken up by a number of standardsdeveloping organizations. While there hasbeen progress in the development of openhealthcare information technology standards,implementation of those standards by health-care application vendors and use of standardsbased healthcare applications to provide over-all solutions has progressed at a slower pace.* Corresponding author.

1386-5056/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved.

PII S 1 386 -5056 (97 )00119 -6

J. Harrington et al. / International Journal of Medical Informatics 48 (1998) 137–143138

Fig. 1. Barriers to diffusion of standards for interoperability.

It is against this background that the An-dover Working Group was formed. The ob-jective of the Andover Working Group is toaccelerate and broadly deliver standards-based solutions for healthcare which featureplug and play interoperability across the con-tinuum of care. In this paper, the organiza-tion, process and deliverables of the AndoverWorking Group are discussed and a descrip-tion of what they contributed to achieve theirobjective is also given.

2. Removal of barriers to diffusion ofstandards

Consider Fig. 1, which depicts the processby which standards for interoperability be-come a part of operational solutions forhealthcare enterprises. Once a standard forinteroperability between healthcare applica-tions is developed, the healthcare applicationdeveloper must then incorporate the relevantportions of the standard in the implementa-tion of a specific healthcare application.When a number of application developers

have indicated support for the standard byimplementing it in their applications, the ap-propriate set of those applications form thebasis for integration into an overall solutionfor a particular healthcare enterprise. Finally,when an overall solution is integrated anddeployed, it remains for the operational staffof the healthcare enterprise to manage thesystem on a day to day basis and to evolvethe system as new requirements arise.

Unfortunately, there are barriers in each ofthe steps involved in moving from a stan-dards development to the operational use ofa healthcare information system based onthose standards. Broadly speaking the barri-ers fall into two categories:� Lack of a precise, complete specification

which can be validated.� Lack of middleware, and tools supporting

implementation, integration and opera-tion.

As shown in Fig. 2, the approach taken bythe Andover Working Group is to removethe implementation, integration and opera-tion barriers by:

J. Harrington et al. / International Journal of Medical Informatics 48 (1998) 137–143 139

Fig. 2. The Andover Working Group approach to the removal of barriers.

� Defining Information Models and Mes-sage Profiles which are precise, completeand capable of validation.

� Developing component based middlewareand tools which support the MessageProfiles in terms of:� Message Factories for composing, re-

ceiving and validating messages.� Message Communicators for defining

message topology and routing mes-sages.

� Administration Tools for configuring,managing, and evolving the system.

The Andover Working Group does not de-velop standards. It adds value to the deploy-ment of standards based solutions bydeveloping multilateral profiles which areprecise and complete. It also adds value bydefining, and implementing middleware andtools which facilitate all phases of deployingstandards based systems in a heterogeneous,multivendor environment.

3. Andover Working Group organization andprocess

The Andover Working Group is an openorganization. Currently, there are threeclasses of membership namely, Core, Sup-porting, and Afffiliate. Calls for participationas a Core member are issued on a yearlybasis, where membership is open to any orga-nization for a period of several months, afterwhich, it is closed until the next call forparticipation.

3.1. Core members

� Dedicate a full time senior technical re-source.

� Participate in monthly meetings.� Contribute to the specification.� Commit to embedding the software into

applications.� Receive early releases of the software.

J. Harrington et al. / International Journal of Medical Informatics 48 (1998) 137–143140

3.2. Supporting members

� Participate in annual meetings.� Receive early releases of the specifications.� Provide feedback on specifications.

3.3. Affiliate members

� Specific working affiliations between An-dover Working Group and other organiza-tions.The membership of the Andover Working

Group consists of Healthcare providers, appli-cation software vendors, integration tool ven-dors and system integrators. When theAndover Working Group was first announcedin March of 1996, there were 12 Core and 15Supporting members. By October of 1997, thisnumber increased to 24 Core and 240 Sup-porting members, representing a broad spec-trum of the healthcare information technologyindustry.

By dedicating a full time senior resource,Core members provide the breadth and depthof technical expertise, as well as the continuityneeded to quickly develop the specifications.By committing to the commercial release ofproducts based on specifications, the Coremembers are strongly motivated toward mak-ing rapid progress.

The supporting members provide evengreater breadth in terms of industry represen-tation, while the affiliated members provide amechanism for coordination with othergroups with related objectives. For example,the Andover Working Group has an affiliatedmember relationship with the MicrosoftHealthcare Users Group (MS-HUG) ActiveXfor Healthcare Committee (AHC). As part ofthis affiliation, the two groups have agreed touse the HL7 Special Interest Group on ObjectTechnology as a common basis for object-ori-ented representation of HL7 messages. Inaddition, the Andover Working Group has

provided both the Applications ProgrammerInterface and the Message Profiles that havebeen developed by the Andover WorkingGroup to the MS-MUG AHC to serve as acommon starting point for the groups activi-ties.

One of the cornerstones of the AndoverWorking Group is that the Information Mod-els, Message Profiles, and Application Pro-grammer Interfaces developed by the groupwill be publicly available upon commercialrelease of the specifications and software.

4. Message profiles

The core members provide domain exper-tise which is the key to providing precise andcomplete information models and messageprofiles (Fig. 3). The initial goal of the An-dover Working Group was to demonstratethat the application of a systematic process forinformation modeling and message profilingwould permit multilateral profiles to be devel-oped with much less effort than is currentlyexpended with multiple bilateral agreements.Given the fact that this was a new processinvolving a large number of organizations, theinitial focus was purposely kept narrow whileensuring that it was sufficiently broad enoughto be of commercial interest. The initial focusof the Andover Working Group was on theHL7 Version 2.2 Standard and, in order toquickly demonstrate the utility of the overallprocess, was further focused on:� Admission, discharge and transfer.� Order entry.� Observations reporting.The process used by the Andover WorkingGroup is based on the Use Case Modeling,Information Modeling and Message Specifica-tion approaches, developed by the IEEEP1157.1 [2], CEN TC251 [3] and HL7 [4]Standards Developing Organizations.

J. Harrington et al. / International Journal of Medical Informatics 48 (1998) 137–143 141

Fig. 3. The Andover Working Group Core members providing domain expertise.

The Andover Working Group messageprofiles account for both the static structuralaspects of the message as well as the dynamicinteractions between the source and the re-ceiver. Each static profile represents a partic-ular specialization of HL7 base message inwhich all options have been removed and allfields are precisely specified. Each profile isuniquely identified by an ISO ASN.1 iden-tifier. The use of a unique identifier for profi-les provides a basis for the ‘yellow pages’capability of identifying which vendors sup-port a given profile. Each profile represents averifiable contract in terms of the responsibil-ities of both the source and the receiver of themessage.

The Andover Working Group has nowturned its attention to a broad coverage ofthe HL7 Version 2.3 specification, basedon the successful development of messageprofiles for the initial domain of HL7 Version2.2.

The Andover Working Group has workedclosely with the HL7 Standards DevelopingOrganization in the development of the infor-mation models and message profiles. In par-ticular, there has been a two way flow ofinformation regarding the application of themessage development process to profiling ofHL7 messages, the SIGOBT specificationsfor object-oriented representation of HL7messages, and mechanisms for the registra-tion of message profiles. In September 1997,in fulfillment of an agreement with the HL7Organization which permits the AndoverWorking Group to use parts of the HL7Information Model and Message Specifica-tions in developing Message Profiles, the An-dover Working Group submitted theInformation Model and Message Profiles tothe HL7 Executive Committee to be used byHL7.

The Andover Working Group has pro-vided additional confidence in the efficacy of

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the new process for message development byproviding a real world use of the process bywhich HL7 plans to develop Version 3.0.

5. Component middleware

In addition to defining multilateral profiles,the Andover Working Group is defining andimplementing distributed object-orientedcomponent middleware and software toolswhich support the application developer, sys-tems integrator, and systems operator in eachof the phases of deploying standards basedsystems.

The Message Factory Component providesthe application programmer with a view ofHL7 messaging which maps to the develop-ment paradigm familiar to the programmer.The message factory supports both tradi-tional HL7 encoding rules as well as thenewer object-oriented representations definedby the SIGOBT. Using the Message factory,the C+ + , ActiveX or Corba developershows the HL7 message which maps to thedevelopers environment. In addition, a par-ticular type of Message Factory supportsconventional TCP/IP HL7 encoding rulesthrough a ‘Proxy’ connection which mapsbetween the SIGOBT representation of mes-sages and HL7 encoding rules representa-tions. The Proxy Message Factory provides amechanism for existing applications to easilyinteroperate with a component based applica-tion system.

In addition to providing the programmerwith a convenient view of HL7 messages, theMessage Factory provides the capability forvalidation of messages at run-time basedupon the static and dynamic Message Profi-les.

The Message Communicator Componentprovides the capability for routing messagesaccording to the topology defined by a sys-

tems integrator or evolved by the operationsstaff. In conjunction with the AdministrationTool, the Message Communicator provideseither the systems integrator or the Opera-tions Staff with the ability to define andimplement any legal topology defined by a setof applications and their associated static anddynamic profiles. One of the key elements ofthe plug and play demonstrated by the An-dover Working Group is that the individualvendors do not need to be involved in theinitial configuration and operational evolu-tion of the system.

The Enterprise Communication Frame-work (ECF) is comprised of the InformationModels and Message Profiles, Message Fac-tory, Message Communicator, and Adminis-tration Tool.

6. Demonstration

The Andover Working Group has devel-oped and continues to evolve a multivendordemonstration which is based on an actualepisode of care of a patient with a cardiacproblem. The demonstration involves com-mercial applications running on multiplehardware and operating system platformscommunicating using the ECF developed bythe Andover Working Group. The demon-stration serves as both a proof point as wellas a testbed for evolution of the ECF.

7. Conclusions

The Andover Working Group has demon-strated that the use of precise, registered mes-sage profiles, combined with object-orientedmiddleware supporting the application devel-oper, systems integrator, and systems opera-tor, will significantly reduce the barriers tothe use of standards for interoperability

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among healthcare applications. The AndoverWorking Group is currently in the process ofexpanding its work program to include theIEEE 1073 Medical Information Bus (MIB)and DICOM standards.

References

[1] HIMSS, HIMMS/Hewlett Packard Leadership

Survey, Healthcare Information and ManagementSystems Society, Chicago, 1997.

[2] IEEE, IEEE P1157.1 Standard for HealthcareData Interchange-Information Model Methods,IEEE, NJ, 1996.

[3] CEN TC 251, Methodology for the Developmentof Health Care Messages, European Committeefor Standardization, Technical Committee 251,Belgium, 1995.

[4] HL7, Message Development Framework, HL7,Ann Arbor, MI, 1997.

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