Reference Models ﻣﺪﻝ ﻫﺎی ﻣﺮﺟﻊ ﻣﻌﻤﺎﺭی

Table of Content n What is a reference model? (10%) n Two reference model samples n OASIS SOA (10%) n OSI reference model (3%) n FEA reference model consisting of : n Performance RM (16%) n Business RM (13%) n Service RM (10%) n Technical RM (10%) n Data RM (10% ) n Relating FEA reference models to each other (10%) Pegah Nejat Reference Models 2

What is a reference model? n A reference model is an abstract framework for understanding significant relationships among the entities of some environment. n 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. Pegah Nejat Reference Models 3

An abstraction hierarchy Alignment to specific requirements Concrete (actual) Architecture Reference Model Conceptualization Pegah Nejat Reference Models 4

An example on this abstraction hierarchy : providing housing n Reference Model n Concepts : eating area, hygiene area, sleeping area n Relationships: physical separation between eating area and hygiene area n Reference Architecture n Bedroom , kitchen , WC , hallway n There may be several reference architectures for one reference models e. g. reference architecture for an apartment , hotel rooms , a space station , … n Concrete (actual) Architecture n Blueprints for a specific house: where to put windows , their size, … Pegah Nejat Reference Models 5

OASIS SOA : a reference model for SOA architectures n Goal : to define the essence of service oriented architecture, and emerge with a vocabulary and a common understanding of SOA. n A basic definition of SOA : n Service Oriented Architecture (SOA) is a paradigm for organizing and utilizing distributed capabilities that may be under the control of different ownership domains. Pegah Nejat Reference Models 6

OASIS SOA Reference Model Main Concepts Pegah Nejat Reference Models 7

OASIS SOA Reference Model Relationships Pegah Nejat Reference Models 8

OSI Reference Model n a layered abstract description for communications and computer network protocol design. Pegah Nejat Reference Models 9

FEA reference models n 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. n Goals: n n n ease sharing of information and resources across federal agencies reduce costs improve citizen services Pegah Nejat Reference Models 10

Performance reference Model n a standardized framework to measure the performance of major IT investments and their contribution to program performance n Goals: n n n improve strategic and daily decision-making Improve the alignment of inputs to outputs and outcomes Identify performance improvement opportunities Pegah Nejat Reference Models 11

PRM (cont ‘d) n Six Measurement Areas Pegah Nejat Reference Models 12

PRM (cont ‘d) n Measurement Areas n Measurement Categories: n Collections within each measurement area describing the attribute or characteristic to be measured n Measurement Groupings: n Further refinement of categories into specific types of measurement indicators n Measurement Indicators: n The specific measures, e. g. , number and/or percentage of customers satisfied Pegah Nejat Reference Models 13

PRM (cont ‘d) n Mission and Business Results MA Identifies the extent to which those purposes are being achieved. Customer Results MA n captures how well an agency or specific process within an agency is serving its customers—and ultimately citizens. Processes and Activities MA n captures key aspects of processes or activities required to be monitored and/or improved. Technology MA n captures key elements of performance directly relating to the IT initiative Human Capital MA : under construction! Other Fixed Assets MA : under construction! n n n Pegah Nejat Reference Models 14

PRM (cont ‘d) – A piece of PRM table Pegah Nejat Reference Models 15

Business Reference Model n Hierarchical construct n Describing day-to-day business operations of the Federal government n function-driven n independent of the agencies that perform them Pegah Nejat Reference Models 16

BRM (cont ‘d) Pegah Nejat Reference Models 17

BRM (cont ‘d) n Services for citizens: n high-level categories relating to the purpose of government n Mode of Delivery n the mechanisms the government uses to achieve its purpose n Support Delivery of Services n The support functions necessary to conduct government operations n Management of Government Resources n the resource management functions that support all areas of the government’s business Pegah Nejat Reference Models 18

BRM (cont ‘d) – sample piece of the hierarchy Pegah Nejat Reference Models 19

Service Reference Model n a business and performance- driven, functional framework that classifies Service Components with respect to how they support business and/or performance objectives. n The model aids in recommending service capabilities to support the reuse of business components and services across the federal government. Pegah Nejat Reference Models 20

SRM (cont ‘d) n Service Domain n provide a high-level view of the services and capabilities that support enterprise and organizational processes and applications n differentiated by their business-oriented capability n Service Type n further categorize and define the capabilities of each Domain n Component n provide the “building blocks’ to deliver the Component capability to the business n a self contained business process or service with predetermined functionality that may be exposed through a business or technology interface. Pegah Nejat Reference Models 21

SRM (cont ‘d) n Customer Preferences Grouping shown below as an example Pegah Nejat Reference Models 22

Technical Reference Model n a component-driven, technical framework n used to categorize the standards, specifications, and technologies that support and enable the delivery of service components and capabilities. Pegah Nejat Reference Models 23

TRM (cont ‘d) Pegah Nejat Reference Models 24

DRM n 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: n Data Context : define a standard approach for agencies to categorize their data , enable the business context of data to be well understood n n 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 n n n Data Object Data Property Data Representation Pegah Nejat Reference Models 25

An example An organization within the federal government provides services which contribute to the health of citizens Business Area = Services for Citizens n Lo. B (Line of Business) = Health n n n Subject Area = Health Super Type = immunization Data Object = vaccine Data Property = type , weight , etc Data Representation = plain text Pegah Nejat Reference Models 26

How DRM is used to enable collaboration n Organization A uses the DRM to categorize its data (using the BRM) into a business context. n Organization B identifies Organization A’s available data through its business context. n Organization A uses the DRM to publish the detailed structure of the actual data element (in support of the business context). n Organizations A and B determine if, in fact, the data produced by Organization A will meet the needs of Organization B. n Once Organizations A and B determine that the data can be reused, the information exchange package is used to transmit the data. Pegah Nejat Reference Models 27

A reference Model for FEA Reference Model! (relationships between XRMs) n The Lo. B represents organizations that have a common business or program interest. n Subject Area = Lo. B from BRM n Super Type = Sub-function of Lo. B from BRM n In PRM: MA Lo. B Measurement Area Lo. B sub-function Pegah Nejat Measurement Grouping sub-function Reference Models Measurement Category 28

A reference Model for FEA Reference Model! (relationships between XRMs)(cont) n TRM provides a framework for categorizing those technologies and standards that can be used to exchange and deliver service components (from SRM) n 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 n There exists no behavior model n Pegah Nejat Reference Models 29

A reference Model for FEA Reference Model! (relationships between XRMs)(cont) BRM DRM PRM SOA SRM TRM Pegah Nejat Reference Models 30