ciootreg.ppt 4/11/98 1 gary a. ham battelle memorial institute possible opportunities for...

ciootreg.ppt4/11/98 1

Gary A. HamBattelle Memorial Institute

Possible Opportunities for Integrating a “Registry

Service” in a Distributed Object Environment



Objectives

Consider ways to use the value inherent in registry information as more than just a static reference.

In particular are their ways to make a registry act as information resource that helps resolve architectural mismatch and semantic conflict in the day-to-day operation within a distributed object architecture?

Also, can we build a capability to use the registry for automated or semi-automated maintenance of system interface definitions?



The CPR Interoperability using Object Oriented Technology (CIOOT)

Initiative

Executive Agency Health Affairs



Background - Threat

Loss of competitive advantage via inefficient information management» Contingency support environment» Managed care environment» Paper records break the medical

informatics loop Compromise of security, privacy,

confidentiality



Background - The Medical Informatics

Loop

Manage

Deliver

Assess



The Main Problem

Manage

De liver

Assess

Paper records canPaper records canbreak the loopbreak the loop

Therefore....Therefore....



The CPR Advantage

Manage

DeliverAssess

Information must be captured in digital form at the point of service for reuse near real time throughout the process at multiple levels.

CPR



Background - Situation

Automated Information Systems (AIS) Crisis» Stovepipes

» Maintenance costs

» Slow to develop and change

» User dissatisfaction

Parallels AIS crisis in industry where traditional approaches maintained

Multiple stakeholders, operational settings, legacy systems, functional activities



Background - Mission

CHCS II Program Office» Via the CPR, provide MHS decision makers with

the integrated information resources necessary to optimize health service in managed care and contingency support environments

CIOOT» Provide CBA with a viable technical alternative

toward the development of the interoperability infrastructure for CHCS II and its CPR



Strategy - Operational Concept

StandardUser Interface

COM+ / CORBA / Java

Bridge

Master Broker

(Integration Software

Suite)Specialized

ServicesCommon Services

TerminologyServices

Clinical Data

Repository

COTS #1ObjectInterface

COTS #2ObjectInterface

Master Patient Index

ObjectInterface

LEGACY #1 ObjectWrapper

LEGACY #2 ObjectWrapper



Accomplishments to Date

Architecture taking shape per C4ISR Framework 2.0 Industry OO methods tailored to DoD objectives; leverage

legacy systems Detailed collaborative process established; working Key tools acquired; being integrated for total life cycle RT Growing/attracting trained workers Networked with industry OOT community Best industry practices implemented - SEI CMM Successful proof of concept demo



Risks / Challenges

Magnitude of complexity

Resistance to paradigm change; waterfall mindset / formats

External dependencies; Lexicon, CRDB; burned before

Affordable, experienced staff, esp. technical; dedication to longer view

CHCS software development coordination



Magnitude of Complexity

Multiple heterogeneous systems

Customization even within like systems

Differing requirements

» Aid station vs. clinics vs. hospitals vs. teaching hospitals

» Stateside vs. overseas vs. forward deployed

» Peacetime vs. war scenario

» Managed care with differing regional contractors

Each item of complexity adds to the likelihood of semantic and architectural mismatches that will need resolution



A Taxonomy of Possible Conflicts*

Identity - Same concept represented by different objects in different local databases

Schema

» Naming - Homonyms and synonyms

» Structural - Concepts represented by different constructs (a method in one database and a class in another) or same construct used but with different structure (methods and/or parameters)

Semantic - Same concept interpreted differently in different databases

Data - Data Values of the same entity are different in different databases

* From: Evaggelia Pitoura, Omran Bukhres, and Ahmed Elmagarmid, “Object Orientation in Multidatabase Systems,”ACM Computing Surveys, Vol.27, no. 2, June 1995.



Manage Interface Mismatches

Initial Interfaces design IAW known “Business Rules”

Errors are caused by:

» Design errors

» Errors induced during maintenance or incremental development

Goals

» Define dynamic interfaces that monitor maintenance and adjust for it using “ontological” services.

» Define “exception” interfaces that process exceptions through “ontological/lexical” services.

» Al least identify where and why a interface error occurred.



Manage “Ontological” Implementations

Serve as a pointer from to/from lexicons/ontologies to those terms which are actually in use

Identify registered concepts not covered in the lexical/ontological engines as gaps in coverage.

Serve as persistent storage for an Meta Object Facility (MOF) implementation (Note: The CORBA MOF appears to have no notion of stewardship other than the concept of “name space”)

Translate from legacy to “standard” at interface nodes by automated distribution from the central registry



Serve as an On Line Reference for Relevant CORBA Services

Naming Service - “it is the responsibility of the higher-level software to administer the name space.” (CORBAServices)

Relationship Service?

Query Service - as a synonym finder?

CORBAmed Lexical Service?

CORBAmed Person Identification Service?



Set Scope for Modeling

Enter only concepts that are in use and required by the enterprise (i. e., have stewards responsible for their maintenance) into an information model.

Reduces the chance that relationships that are not tied to required functionality enter an enterprise model.

Reduces the likelihood of “shelfware” models.

Allows for “modeling the standards” rather than “standardizing the models.”



Final Thoughts

Registries are there to publicize defined “standards.”

Hopefully the good stuff wins and the bad stuff loses.

Even when the “second best” wins, we gain from the network effect of enhanced reuse.

Only when standards are imposed unilaterally, without recourse, are really bad things likely to happen.

The blessing of the registry is that it allows for standards to be marketed. What works will be chosen. On-line use will work the same way.

But then you all know that. So, I’m just preaching to the choir.

ciootreg.ppt 4/11/98 1 gary a. ham battelle memorial institute possible opportunities for...

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