Reference Models

مدل های مرجع معماری

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Table of Content

What is a reference model? (10%) Two reference model samples

OASIS SOA (10%) OSI reference model (3%)

FEA reference model consisting of : Performance RM (16%) Business RM (13%) Service RM (10%) Technical RM (10%) Data RM (10% )

Relating FEA reference models to each other (10%)

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What is a reference model?

A reference model is an abstract framework for understanding significant relationships among the entities of some environment.

Reference model consists of a minimal set of unifying concepts, principals and relationships within a particular problem domain, and is independent of specific standards, technologies, implementations, or other concrete details.

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An abstraction hierarchy

Reference Model

Reference Architecture

Concrete (actual) Architecture

Alignment to specific

requirements

Conceptualization

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An example on this abstraction hierarchy : providing housing

Reference Model Concepts : eating area, hygiene area, sleeping area Relationships: physical separation between eating

area and hygiene area Reference Architecture

Bedroom , kitchen , WC , hallway There may be several reference architectures for one

reference models e.g. reference architecture for an apartment , hotel rooms , a space station , …

Concrete (actual) Architecture Blueprints for a specific house: where to put windows ,

their size, …

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OASIS SOA : a reference model for SOA architectures

Goal : to define the essence of service oriented architecture, and emerge with a vocabulary and a common understanding of SOA.

A basic definition of SOA : Service Oriented Architecture (SOA) is a

paradigm for organizing and utilizing distributed capabilities that may be under the control of different ownership domains.

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OASIS SOA Reference Model Main Concepts

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OASIS SOA Reference Model Relationships

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OSI Reference Model

a layered abstract description for communications and computer network protocol design.

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FEA reference models

The Federal Enterprise Architecture is an initiative of the Office of Management and Budget that aims to comply with the Clinger-Cohen Act and provide a common methodology for information technology (IT) acquisition in the United States federal government.

Goals: ease sharing of information and resources across

federal agencies reduce costs improve citizen services

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Performance reference Model

a standardized framework to measure the performance of major IT investments and their contribution to program performance

Goals: improve strategic and daily

decision-making Improve the alignment of

inputs to outputs and outcomes

Identify performance improvement opportunities

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PRM (cont ‘d)

Six Measurement Areas

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PRM (cont ‘d)

Measurement Areas Measurement Categories:

Collections within each measurement area describing the attribute or characteristic to be measured

Measurement Groupings: Further refinement of categories into specific types of

measurement indicators Measurement Indicators:

The specific measures, e.g., number and/or percentage of customers satisfied

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PRM (cont ‘d)

Mission and Business Results MA Identifies the extent to which those purposes are being

achieved. Customer Results MA

captures how well an agency or specific process within an agency is serving its customers—and ultimately citizens.

Processes and Activities MA captures key aspects of processes or activities required to

be monitored and/or improved. Technology MA

captures key elements of performance directly relating to the IT initiative

Human Capital MA : under construction! Other Fixed Assets MA : under construction!

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PRM (cont ‘d) – A piece of PRM table

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Business Reference Model

Hierarchical construct Describing day-to-day

business operations of the Federal government

function-driven independent of the agencies

that perform them

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BRM (cont ‘d)

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BRM (cont ‘d)

Services for citizens: high-level categories relating to the purpose of

government Mode of Delivery

the mechanisms the government uses to achieve its purpose

Support Delivery of Services The support functions necessary to conduct

government operations Management of Government Resources

the resource management functions that support all areas of the government’s business

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BRM (cont ‘d) – sample piece of the hierarchy

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Service Reference Model

a business and performance-driven, functional framework that classifies Service Components with respect to how they support business and/or performance objectives.

The model aids in recommending service capabilities to support the reuse of business components and services across the federal government.

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SRM (cont ‘d)

Service Domain provide a high-level view of the services and

capabilities that support enterprise and organizational processes and applications

differentiated by their business-oriented capability Service Type

further categorize and define the capabilities of each Domain

Component provide the “building blocks’ to deliver the Component

capability to the business a self contained business process or service with

predetermined functionality that may be exposed through a business or technology interface.

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SRM (cont ‘d)

Customer Preferences Grouping shown below as an example

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Technical Reference Model

a component-driven, technical framework

used to categorize the standards, specifications, and technologies that support and enable the delivery of service components and capabilities.

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TRM (cont ‘d)

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DRM intended to promote the common

identification, use, and appropriate sharing of data/information across the federal government through its standardization of data in the following three areas: Data Context : define a standard approach

for agencies to categorize their data , enable the business context of data to be well understood

Subject Area Super Type

Data Sharing : define a standard message structure known as Information Exchange Package

Data description : define a standard approach to describing an agency ‘s data

Data Object Data Property Data Representation

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An example

An organization within the federal government provides services which contribute to the health of citizens Business Area = Services for Citizens LoB (Line of Business) = Health

Subject Area = Health Super Type = immunization Data Object = vaccine Data Property = type , weight , etc Data Representation = plain text

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How DRM is used to enable collaboration

Organization A uses the DRM to categorize its data (using the BRM) into a business context.

Organization B identifies Organization A’s available data through its business context.

Organization A uses the DRM to publish the detailed structure of the actual data element (in support of the business context).

Organizations A and B determine if, in fact, the data produced by Organization A will meet the needs of Organization B.

Once Organizations A and B determine that the data can be re-used, the information exchange package is used to transmit the data.

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A reference Model for FEA Reference Model! (relationships between XRMs) The LoB represents organizations that have a

common business or program interest. Subject Area = LoB from BRM Super Type = Sub-function of LoB from BRM In PRM:

MA

LoB LoB LoB

sub-functionsub-function

Measurement Grouping

Measurement Category

Measurement Area

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A reference Model for FEA Reference Model! (relationships between XRMs)(cont)

TRM provides a framework for categorizing those technologies and standards that can be used to exchange and deliver service components (from SRM)

DRM provides for a specific type of SOA in which there is no action , only exchange of information. Considering OASIS SOA : Information model is expressed using DRM There exists no behavior model

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A reference Model for FEA Reference Model! (relationships between XRMs)(cont)

PRM

BRM

DRM

TRM

SOA

SRM