E-Business & Web Technology - 1 © Minder Chen, 2003-2004

IT Architectures

Minder Chen, Ph.D. Associate Professor of ISOM

George Mason UniversityFairfax, VA 22030mchen@gmu.edu

E-Business & Web Technology - 2 © Minder Chen, 2003-2004

Information Systems Triad

OperationalDatabase

InformationalDatabase

EnterpriseWorkflow

OLTP DSSEIS

Data Information

Knowledge

Messaging Systems

Workgroup Workflow

BusinessProcessWorkflow

E-Business & Web Technology - 3 © Minder Chen, 2003-2004

The Extended Enterprise

E-Business: Virtual and Dynamic Enterprise

SuppliersBackOffice

FrontOffice

Customers

Buy Make/Add Value Sell

Supply Chain Back Office Integration Demand Chain

ManufacturingFinance

Engineering

SalesSupport/Service

Marketing

Supply Chain Management Customer Relationship Management

Enterprise Resource Planning

© Minder Chen, 2001-2002

E-Business & Web Technology - 4 © Minder Chen, 2003-2004

LAN-Based Client/Sever Architecture

PCs

LAN

Printer

• Circa: Later 80’s

• Multiple servers provide file, print, communication, data base, and application services to clients

• Servers may be a PC, mini-computer or mainframe computer.

Servers

MiniMainframe

Applications

Storage

WAN: WideAreaNetwork

E-Business & Web Technology - 5 © Minder Chen, 2003-2004

Three Components and Five Style of Client/Server Processing

1. Distributed presentation

2. Remote Presentation

3. Distributed Function

4. Remote Data Management

5. Distributed Data Management

Presentation

Function

DataManagement

2-tier vs. 3-tier

E-Business & Web Technology - 6 © Minder Chen, 2003-2004

Five Styles of Client/Server Systems

Data

Mgmt.

Function

Data

Mgmt.

Data

Mgmt.

Data

Mgmt.

Data

Mgmt.

Presentation

Presentation

Distributed

Presentation

Function

Presentation

Function

Function

Presentation

Remote

Presentation

Distributed

Function

Function

Presentation

RemoteData

Management

DistributedData

Management

Function

Presentation

Data

Mgmt.

Network

E-Business & Web Technology - 7 © Minder Chen, 2003-2004

Application Model: Relationships of Categories of Services

E-Business & Web Technology - 8 © Minder Chen, 2003-2004

Web Applications

Web sites (Content-oriented)

Web-based Applications

C/S Applications (Transaction-oriented)

E-Business & Web Technology - 9 © Minder Chen, 2003-2004

3-tier Web Applications

Web server

Server-Side Script

Business Object

(Web browser)

File SystemsSMTP Server (send email)

ASP.NET

E-Business & Web Technology - 10 © Minder Chen, 2003-2004

Logical Application Architecture

RelationalDatabase

GraphicalUserInterface

RelationalDatabase

GraphicalUserInterface

BusinessObjectModel

GraphicalUserInterface

BusinessObjectModel

RelationalDatabase

2-tier 3-tier True 3-tier

Data ServiceClass

E-Business & Web Technology - 11 © Minder Chen, 2003-2004

Physical Application Architecture

Relational Database Server(s)

Client CWWW Browser

WebServer

HTMLCGI

ASP Java

Business ObjectServices

Business ObjectEngine

Application

Business ObjectServices

Client A

Business ObjectEngine

Thinner client, thicker server

Client BApplication

Business ObjectServices

Business ObjectEngine

Business Object Server

DCOMADO/R

CORBA Beans

COMMTS

BeansETS

E-Business & Web Technology - 12 © Minder Chen, 2003-2004

Building N-Tier Applications

Applications = Data Services + Business Logic + Presentation Logic

Analysis and Design =

Data Modeling + Process Modeling + GUI Design

ApplicationArchitecture Design

Database / XMLApplication Servers

• Business Objects• Data Access Object

Presentation Layers• Windows• Browsers• Mobile Devices

© Minder Chen, 2001-2002

OOAD(UML)

WebServi

ce

E-Business & Web Technology - 13 © Minder Chen, 2003-2004

Distributed Computing Architecture

ThinClient

RichClient

Firewall

Databases Legacy Systems

ExternalApplications

Business LogicData

Web Server

Web Server

LAN

/ Internet

Application Server

Presentation

HTMLXML

(B2B)

Development Tools

Systems Services

E-Business & Web Technology - 14 © Minder Chen, 2003-2004

Application Size and Technology

E-Business & Web Technology - 15 © Minder Chen, 2003-2004

EC Infrastructure

E-Business & Web Technology - 16 © Minder Chen, 2003-2004

Application Server - Compaq PIII 500

Client WorkstationHP Kayak XU-400

Database Server - Compaq PIII 500

SAP R/3Comment

Client Source CodeComment

(client.exe)

Oracle 8Comment

TCP/IP

TCP/IP

Sample UML Deployment Diagram

UML: Unified Modeling Language; An Object-Oriented Analysis and Design Method