Version 3:Is it Real, or is it Memorex?

Wes RishelVice-chair, Technical Steering Committee

Wes@Rishel.comwww.Rishel.com

9/14/98 5©1998 by HL7 & Wes Rishel

Version 3 Message Definition ProcessUse Case Model

InteractionModel

HierarchicalMessage

Description

ReferenceInformation Model

DomainInformation

Model

MessageInformation

Model

MessageObject

Diagram

CommonMessageElement

Definition

9/14/98 6©1998 by HL7 & Wes Rishel

Use Case ModelUse Case Model

InteractionModel

HierarchicalMessage

Description

ReferenceInformation Model

DomainInformation

Model

MessageInformation

Model

MessageObject

Diagram

CommonMessageElement

Definition

9/14/98 8©1998 by HL7 & Wes Rishel

Information ModelsUse Case Model

InteractionModel

HierarchicalMessage

Description

ReferenceInformation Model

DomainInformation

Model

MessageInformation

Model

MessageObject

Diagram

CommonMessageElement

Definition

9/14/98 13©1998 by HL7 & Wes Rishel

Interaction ModelUse Case Model

InteractionModel

HierarchicalMessage

Description

ReferenceInformation Model

DomainInformation

Model

MessageInformation

Model

MessageObject

Diagram

CommonMessageElement

Definition

9/14/98 16©1998 by HL7 & Wes Rishel

Message Object DiagramUse Case Model

InteractionModel

HierarchicalMessage

Description

ReferenceInformation Model

DomainInformation

Model

MessageInformation

Model

MessageObject

Diagram

CommonMessageElement

Definition

9/14/98 31©1998 by HL7 & Wes Rishel

Hierarchical Message DescriptionUse Case Model

InteractionModel

HierarchicalMessage

Description

ReferenceInformation Model

DomainInformation

Model

MessageInformation

Model

MessageObject

Diagram

CommonMessageElement

Definition

9/14/98 32©1998 by HL7 & Wes Rishel

HMD Has Three Parts

Information Model

Mapping

Message Elements

Message Structures

Message Format 1

Message Format 2

Person Object PSN Segment Yes NoName attrib Name data field Yes --

Object from Message Object Diagram

9/14/98 34©1998 by HL7 & Wes Rishel

Rows in HMD Match Fields in Message

ENC|A|TE|ENC703421||2|19970301|I|1998011110815|ABC|IPChoice|I IPE||4 PADM|1998011110815|{3^OBSERVATION^99ARE}|{1^PHYS REFERRAL^99ARF}|ED|I|N|NECPTP|||||Y|U|19670329|Dallas,TX||HS|M|D|{Jones^Sam^Houston}|W|BAPT||X454337PCP|{Anderson^Sara^^Dr^MD}|[{WPN^^206^2721234}^{ASN^^206^5551212}]|15892BL|AccountList PTBA|X1256243|U^UNBILLED^99BAS|P|A27 PTBA|X1256997|U^UNBILLED^99BAS|C|F13EL|AccountListBL|EncPractList BG|EncPrac ENP|ATT HCP|{Winters^Hubert^S^Dr^MD}|[{WPN^^206^3914871}^{HPN^^206^5551234]|77032 EG|EncPrac BG|EncPrac ENP|CONS HCP|{Scully^Dana^^Dr^MD}|[{WPN^^206^3934871}^{HPN^^206^5556667}]|25122 EG|EncPracEL|EncPractList

Not so fast !

What about XML?

9/14/98 36©1998 by HL7 & Wes Rishel

Conformance Claim

...Relied on by a User

...Describes the sponsor’s Information System

list of HL7-written

statements...

...Leads to an agreement

Offered by a Sponsor...

9/14/98 37©1998 by HL7 & Wes Rishel

Trigger Events, Interactions, App Roles

Pharmacy_order_

Creator

Pharmacy_order_

Manager

Pharmacy_order_

Tracker

Med_order_admin_Manager

Med_order_admin_Historian

Create Unencoded Pharmacy Order

Create Unencoded Pharmacy Order

Provide Filler ID

Create Unencoded Pharmacy OrderX

Convert Unencoded PharmacyOrder to Fully Encoded Order

Convert Unencoded Pharmacy Orderto Fully Encoded OrderX

Create Med Administration OrderCreate Med Administration Order

Create Med Administration OrderX

Report Administered Medications

Report Administered MedicationsYReport Administered Medications

TriggerEvent

Inter-Action

Applic.Role

9/14/98 38©1998 by HL7 & Wes Rishel

Certification

• HL7 “Seal of Approval”

• Certification = Testing

• What do we certify?– That a system passed a test …– … that individually tested one or

more conformance claims.

• In other words … there is no logo that says “100% HL7 Compliant”

9/14/98 39©1998 by HL7 & Wes Rishel

The Change Paradox

It is change, continuing change, inevitable change, that is the dominant factor in society today. No sensible decision can be made any longer without taking into account not only the world as it is, but the world as it will be. . . .

Isaac Asimov (1920–92)

Most of us are about as eager to be changed as we were to be born, and go through our changes in a similar state of shock.

James Baldwin (1924–87)

It is change, continuing change, inevitable change, that is the dominant factor in society today. No sensible decision can be made any longer without taking into account not only the world as it is, but the world as it will be. . . .

Isaac Asimov (1920–92)

Most of us are about as eager to be changed as we were to be born, and go through our changes in a similar state of shock.

James Baldwin (1924–87)

9/14/98 40©1998 by HL7 & Wes Rishel

The Gain (V3 Benefits)

• Interfaces installed much more quickly – reduce sight-specific negotiations– greatly reduce custom programming– asymptote is “plug and play”

• Conformance claims; support for conformance testing

• Functional adaptation to the changing healthcare system

9/14/98 41©1998 by HL7 & Wes Rishel

Other Benefits

• Improved clarity and correctness of specification

• Appropriate to newer communications paradigms

9/14/98 42©1998 by HL7 & Wes Rishel

The Pain?

• Changes to the interface software– subtle, but substantial– segment groups– subsubsubcomponents– recursive types

• Functional changes to systems– more precise specifications– requirement to use data that is received

• Retraining

9/14/98 43©1998 by HL7 & Wes Rishel

Is the Pain worth the Gain?

• Transition costs– retooling of character-stream based interface software– or, adaptation of object-based approaches, with

corresponding benefits– Analyst time to interpret 2.3 transactions and

configure interface engines for 3.0

• The good news– You have a two-year+ head start

9/14/98 44©1998 by HL7 & Wes Rishel

Other Observations on Change

Change is inevitable ...

… inevitably slower than anticipated

Change for marginal benefit gets overrun by newer change

Change begets change

9/14/98 45©1998 by HL7 & Wes Rishel

The Revolution, um, Evolution of XML

• eXtended Markup Language

• Fundamental economic driver is an evolutionary change to the World Wide Web– content-based searching and presentation– management of documents in pieces– indirect links– etc.

• Compatible upgrade to HTML

9/14/98 46©1998 by HL7 & Wes Rishel

XML Benefits Will Beget Other Changes

• Document markup: SGML changes its costume and gets “discovered”

• Self-documenting data files– almost self-parsing

• The begetting happens through– tools,– people,– and hoopla (i.e. the attention of the marketing department)

9/14/98 47©1998 by HL7 & Wes Rishel

XML and Version 3• The syntax handles recursion• Parsers are “free”• Self-documenting data files• XML-related tools

– viewing– testing– conversion

• Availability of trained personnel• LOTS and LOTS of HOOPLA!

9/14/98 48©1998 by HL7 & Wes Rishel

Dr. Asimov Revisited

“No sensible decision can be made any longer without taking into account not only the world as it is, but the world as it will be. . . .”

• Design decisions require cautious optimism about change.

• Five years from now, if V3 does not use XML, people will, at best, be amused by our quaint eccentric ways.

9/14/98 49©1998 by HL7 & Wes Rishel

Describing an HL7 Message Format

HL7-ConformantApplication

HL7-ConformantApplication

Data

HL7MessageCreation

HL7MessageParsing Data

MessageInstance

ITS

ImplementationTechnology

Specifications

HierarchicalMessageDefinition

"Discontinuepharmacy order"

"Send as ASCIIstring in XML

format"

9/14/98 50©1998 by HL7 & Wes Rishel

Technology Layering in V3 Messaging

HL7-Conformant Application

Data

HL7-Conformant Application

ITS-SpecificSoftware

Agent

ITS-SpecificTransfer

Mechanism

HierarchicalMessageDefinition

HL7 Version3.X

HierarchicalMessageDefinition

HL7 Version3.Y

HL7 Type Object Model, v3.X

M essageElem ent

Type

M essageElem ent

Type

M essageElem ent

Type

M essageElem ent

Type

M essageElem ent

Type

M essageElem ent

Type

HL7 MessageProcessing Data

HL7Instance O bject M odel

M sg Elem entInstance

M sg Elem entInstance

M sg Elem entInstance

M sg Elem entInstance

M sg Elem entInstance

M sg Elem entInstance

ITS-SpecificSoftware

Agent HL7 Type Object Model, v3.Y

M essageElem ent

Type

M essageElem ent

Type

M essageElem ent

Type

M essageElem ent

Type

M essageElem ent

Type

M essageElem ent

Type

HL7Instance O bject M odel

M sg Elem entInstance

M sg Elem entInstance

M sg Elem entInstance

M sg Elem entInstance

M sg Elem entInstance

M sg Elem entInstance

HL7 MessageProcessing

9/14/98 51©1998 by HL7 & Wes Rishel

The Gotchas

• Not a patch to an existing parser

• Access to “free” parsers on legacy operating systems

• Message sizes substantially larger

9/14/98 52©1998 by HL7 & Wes Rishel

The Plan• Prototype

– demo at HIMSS in HL7 booth– multiple systems– mixed version 2 and v3/XML– interface engine

• Prototype goals:– evaluate methodology– evaluate parsing difficulty/message size– HOOPLA

9/14/98 53©1998 by HL7 & Wes Rishel

Is it Real?

• The V3 Effort has already profoundly improved HL7

• RIM provides coordinating point for broad array of standards efforts

• Organizational awareness of enabling technologies

• Technology-independence seemingly proven by our current work

9/14/98 54©1998 by HL7 & Wes Rishel

HL7--Not Just Messaging Anymore

Enterprise Com m unications(T rad itiona l H L7 )

DataManagem ent

Models(A rdenS yn tax)

UserInterface System

Mgt

Com m on User Envt

Inform a-tion

Model(V e rs ion3 R IM )

Enterprise Com m unications(T rad itiona l H L7 )

Inform a-tion

Model(V e rs ion3 R IM )

Models(A rdenS yn tax)

Com m on User Envt(C C O W U ser L ink ,P a tien t L ink , e tc .)

9/14/98 55©1998 by HL7 & Wes Rishel

Implementing Version 3 as Change

• End user benefits need to be proven

• Some will derive from RIM improvements currently underway

• Some will derive from being enabled by new enabling technologies

• We are now entering the fray!