http://www.hl7.org.uk

HL7 UK

Advantages and Disadvantages of Middleware

Solutions

Tony Mottram – Indigo 4 Systems

Co-chair HL7 UK Lab Sub-group

http://www.hl7.org.uk

What is Middleware?

• Integration Engine?

• Interface Engine?

• System Emulator?

• Everyone has a different concept.

• There is no single definition of middleware. It varies depending upon what the individual wants it to mean.

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What is Middleware?

• It may emulate another system.

• It may be an Integration Engine.

• It may transform structured messages.

• It may be all of these and more beside.

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Problem

What is Middleware?

A Design Authority Viewpoint

Black Box

Interface

Problem Solved!

What does it do?That’s your problem!It’s a Black Box!

CommunicationTransformation

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What is Middleware?

Another Viewpoint

Integration Engine

PAS Trust Pharmacy

Pathology

High Street Optician

High Street Pharmacy

GP Practice

HL7

XML

EDIFACT

Free TextAnything else I might want

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What is Middleware?

A Middleware Viewpoint

Middleware

PASTrust Pharmacy

Pathology

High Street Optician

High Street Pharmacy

GP Practice

Update/Reference?

Cataract/Glaucoma?

EHR/Results/Requests?

Prescribing/Dispensing?Ordering/Reporting?

ETP/POCT?

Local Takeaway

????????

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What is Middleware?

• It interfaces Applications and Systems.• It’s more and less than an Integration Engine.• It’s not just an on-the-fly message translator.• It stores individual message entities for re-

assembly, grouping and routing.• It provides pseudo-interfaces to other systems -

aiding cross-discipline comprehension and accommodation of differing terminologies.

• It provides controls for each domain by using rules and protocols tailored by users within the domain.

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Unusual Example Requirement

Local Takeaway -> Pathology Request.Destination – Anytown Hospital pathology labDemographics – name, address and phone no.Test Request – Quality test on No. 23 (fried rice)Sample type – Rice Location – white bag in storeSample Container – 7548 - plastic microwavable boxDiagnosis – Customer feels very illRecent History – Same problem last weekFasting – not by choiceResponsible Person – Health Inspector

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Unusual Example Requirement

Pathology ReportDestination – Local TakeawayDemographics – sender name, address and phone no.Sample type – Rice Location – white bin in storeObservation – abnormally high Na and ClObservation – Patna not BasmatiComments – excess salt likely to cause vomiting.Responsible Person – Mr. Chempath

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Is the Communication Understood?

• Safe coding transforms – which is the safest - the code or the rubric – “No. 23” or “fried rice”

• Transform discipline specific jargon to terms which others can understand – Na? Cl? does “salt” have the same meaning?

• Does the message transport method impact upon the safe communication of the data?

• How can I be sure that what you think I said is exactly what I meant?

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Advantages of Middleware?

• Service not System Orientated Architecture.• Allows each discipline to retain control of its own

data and ensure appropriate presentation.• Offers bi-directional human to human, human to

machine and machine to machine communication.• Offers different human interfaces to accommodate

different user bases.• Enables end-to-end communication between

disparate systems.• Aids rationalisation/harmonisation existing

processes.• It can act as a messaging endpoint for systems

which cannot directly support structured messaging.

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Disadvantages of Middleware?

• May increase processing overhead when compared with direct end-to-end messaging.

• Needs collaboration between all stakeholders to establish requirements – understanding every viewpoint can be difficult.

• Rationalising existing processes without jeopardising the outcome may not be possible. The Middleware may have to accommodate them.

• There is no single plug-and-play solution for all existing systems and services – each one will have its own specific quirks.

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Issues for Consideration

• Theoretical Solution – Redesign all Systems and Applications to fully support every structured and unstructured messaging protocol – Green field approach

• Clinical and administrative systems have had significant investment in their design and implementation over long periods – Experience is a important factor

• Processes have been optimised according to local patient requirements and local service facilities – One size does not fit all.

• Reluctance to change something which appears to work effectively - Inertia

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Why Is Middleware Still Used?

• It’s a well tried and tested methodology.• It doesn’t have a major impact upon working

practices.• It’s versatile and forgiving of local anomalies.• Big bang replacement of existing systems with ones

which all speak the same language is not an easy option and has significant clinical risks, huge financial implications and steep learning curves.

• Middleware offers a migration approach which is clinically safer, more cost effective and less disruptive.

• End-to-end messaging is the best solution but it is still a long way off.

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Middleware – You Decide

• Questions?