Ontology & Enterprise Architecture

7/24/2019 Ontology & Enterprise Architecture

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All slides Model Futures 2004-2007 Unless Otherwise Stated

Ontology & Enterprise Architecture

Ian Bailey

[email protected]

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Introduction

Semantic issues with Enterprise Architecture

Examine some of these issues

Ontolo can be a difficult sub ect Especially for those immersed in information theory

Basic introduction to some of the conce ts

The IDEAS Group

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Enter rise Architecture

Multi-Disciplinary

Policy, Process Modelling, Information, Data, Apps,

Networks, etc.

Different levels of abstraction

Types of people (posts), types of organization, types

of systems, etc. Actual systems, locations, etc.

Need a way to

sa what exists or what could exist tie it all together

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erminolo

Large Enterprises have specialist groups and departments.

..and these can differ

service

consultant

analyst modeller

procedurefunction

policy

maker

technical

architect

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IT


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erminolo - 2

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EA & The Real World Very easy to say that EA is just about modelling

But, the models tend to describe actual systems, processes, etc. ome aspec s o an are ve a a e.g. s e a a s us ness a a o

the facility managers

Even models have impact on the daily business

representations of the real world Those same real world things may also be represented in other model

e.g. org structures, system deployments that are also part of the EA

In other words, stratification of model and data is too simplistic anapproach for EA

EA

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Ontolo & Information Conflict

conflictconflict

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Ontolo

Currently much hype about ontology But how much do people really understand about it ?

There are two main types of ontology thatappear n : Formal ontology usually based on AI concepts of

.machine to make decisions.

Philoso hical ontolo usin the best discoveries ofmathematics and philosophy to create a model which

best describes the things were interested in e interest or EA is t e atter, as we re see ing

to have a common understanding

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Ke Ontolo ical Conce ts

Useful to know a few termsa classcar

vw golf

e ore exp a n ng morea sub-class

an individual

my car Where would the service

reference model fit ?

Classes of service

Specialise from process

natural

process

intentional process

service

process

pr n serv ce

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my service, performed 13/11/06


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axonom

But surely if we just need common understanding, all wenee s a axonomy

True up to a point, but all we then have are names, with no idea

A traditional taxonomy e.g. IPSV or the UK Defence Taxonomyis a structure of broader and narrower terms:

class (i.e. type of thing)

individual (i.e. specific thing)

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axonom & Ontolo

class

individual

whole-part relationship

Above shows a typical taxonomy short-cut

An ontology would distinguish between all of

these. In addition, a well-founded ontology can provide

a ood deal more functionalit

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IDEAS Grou

Consisting of representatives from the defenceepar men s o our coun r es:

Australia, Canada, UK, USA + we en an as o servers

Goal is to develop a common model for

architecture

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Structure

Layered approach ar ng rom rs pr nc p es o ensure common un ers an ng a e mos

fundamental level Reaching down to country-specific definitions whose meaning may need to be

understood by other nations

foundationfundamental concepts:

classes, instances, properties

high-level patterns (upper ontology) commonly used relationships:whole-part, sequence, partipation, etc.

common objects (agreed taxonomy)internationally accepted terms:

person, organization, materiel, etc.

national

extension

national

extension

national

extension

national

extension

terminology specific to nations that

which may be useful to other nations

- e.g. Bowman, Bradley FV, etc.

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Foundation

The nations involved were using different modelling

Entity-Relationship

Object-Oriented (inc. UML Meta-Models)

Ontology

All of these modelling approaches are based on formal,

especially as users tend to adopt a given style These differences were makin it hard to establish a common

approach between the nations there was too much scope formisunderstanding between parties

,foundational layer (based on IEEE Candidate UpperOntologies such as SUMO & ISO15926)

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he Lan ua e of Ontolo

Before we can begin the training, it is important thateveryone as a common un ers an ng o e oo s anlanguage of the ontologist

Types (also known as classes, categories, sets)

Tuples(also known as relationships or associations)

Ti s:

Always try to ground your thinking by taking it back to concreteexamples esp. when dealing with types, work with example

.

Draw it as a Venn Diagram (notation to follow)

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Venn Dia ram Notation

The typical Venn diagram is slightly enhanced to deal

An individual that is

an instance of A Subtype

and therefore of A Type

A Type

Type 1

Type2

Type3Colonel

General

CorporalCar

VW Golf

My VW Golf

An individual that is not

an instance of A Subtype

but is an instance of A TypeType2General

An individual that is not

an instance of A Type

ne o o n

Prescotts JagsJohn Prescott

Individual 2MacArthur

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he BORO Methodolo

BORO A methodology for developing business models

Ontologyis the study of what exists BORO provides a formal, step-by-step method to develop an

ontology Ensures that there is no scope-creep due to modelling alone

can preven s a e o ers rom w en ng e scope oug

Provides a way of de-conflicting several stakeholder views (cfSoft Systems)

Results in a formal ontology

Tends towards simplification establishes high-level patterns

model futures This slide Crown Copyright 2007


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he BORO Process

Does it exist in space & time ?

i.e. can you kick it (now, in the past or in the future)

INDIVIDUAL

can be no debate about semantics.

If not is it a t e of Individual or a t e of t e of

individual ? TYPE

What is it a type of ? Always trace back down to individuals again, this de-conflicts semantics for types.

, TUPLE



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Generalisation

The basic BORO process establishes the ontic categories

This is the first essential stage

However, this has not built us an ontology

. .

and this is where the difference with BORO becomes apparent

,

hierarchy that is built is clean. and strange things start to happen high level patterns start

o emerge

..some of them are quite surprising



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What does BORO let us do ?

Compare systems wor s es w rea egacy a a.

The dirtier the data the better works on the assumption that

most data quality problems stem from the fact that systems dono o w a e users wan , so ey s oe- orn n e a a eyactually need.

Comparison is guaranteed accurate provided the BORO methodand criteria for identity are rigidly followed.

Integrate systems ,

automate the conversion between them

Build the next generation of systems Implement the high-level patterns everything else is data Universal applications



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BORO Exam le - Standards

What is a standard ?

A document ?

The act of ratifying an agreement ?

Deal with each of these cases one by one

Work out the types Work out the tuples

Pattern starts to emerge

As more business data from other subject areas is analysed, itecomes apparen a an ar s us a spec a case o a moregeneral end-to-end agreement pattern.



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Unlearnin -1

IT professionals have a lot to unlearn beforethey can work with ontologies

-of the thing, and think about the actual thing

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Unlearnin -2


- -stratification

rank

Colonel

General

Corporal

GeneralEisenhower

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MacArthur


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Unlearnin -3


-relationships with sub-super

rank

General

MacArthur

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Unlearnin -4


the elements position in the ontology defines

,

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Mana in Chan e Over Time

One type of ontology approach deals particularly well

Distinguished between whole life things and the states

they have throughout time e.g. a person

Bornstarted chan ed

MaternityWard

started

school

work job retired

whole-life person

spac

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Mana in Identit

A good ontology will identify the states of the individual

It will also say who owns the identification scheme used

De t. of Education De t of Work

NHS

Health Authority & Pensions

PensionNumber

PupilID Number

Employee

numberNumber

whole-life person

spac

working at

MOD

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Last Slide

What does ontology do for me ? Provides a sin le coherent reference model for the whole enter rise Supports the enterprise architect Supports the applications and data

What do I re uire ? Need to decide type of ontology to use Can I re-use anything out there e.g. IDEAS, ISO15926, SUMO

More than taxonom

Ontology is not about words Its about identifying the nature of things the relationships betweenelements do more to identify them than the names do

What Next ? Try it !

Choose a subject area and model it Links http://www.boroprogram.org/ http://www.ideasgroup.org

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Ontology & Enterprise Architecture