Class 7 Distributing Business and Systems Asper School of Business - MBA Program 6150 Management of Information Systems & Technology April-June 2009 Instructor:

Class 7

Distributing Business and Systems

Asper School of Business - MBA Program6150 Management of Information Systems & Technology

April-June 2009Instructor: Bob Travica

Updated May 2009

Outline

• Strategies of Distributing Business & Systems

• Concept of Distributed Systems

• Client-Server Architecture

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• Messages for change leadership

Strategies of Distributing Business & Systems

• Dispersed org. entities can have different information needs –

low highSpatial dispersion

Manufacturer fo

r loca

l market a

nd

exports (s

ourcing & producti

on vs.

marketing & sa

les) Fast food

franch

iser

(McD

onald’s;

finances v

s.

sourci

ng, HR,

sales)

Multinatio

nal Manufactu

rer

(Ford; global so

urcing, in

ternational

R+D, producti

on, marketin

g…)

• Organizations dispersed in space (individuals, groups, units; e.g., salespeople in master case)

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• Information systems have to support different strategies of distributing business

• Inter-cultural aspect (master case)

Application Software (Functionality, Data processing)

Data(Data mgmt, Database)

User Interface(Presentation, input/output screens)

Information System Parts(resources, services)

Distributed Systems Concept: What Can Be Distributed

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• Any of these parts can be distributed – data, functionality, user interface. If all run by one computer, the system is centralized.

• An aspect of systems architecture (overall design of computing resources).

Distributed Systems: Data View

• Method 1: Central store, distributed access. Role of networks (3i, Northwest Airlines).

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• Rule #1 for distributed systems: Make data available where users need them.

• Method 2: Partition data store. Data fed and searched locally; occasional cross search.

More

Toronto VancouverWinnipeg

Purchasing

Production Sales

• Golden rule: Regardless of the specific architecture, users should not care if a system is distributed and in what manner. Access should be seamless.

• Method 3: Data partitions stored locally in real time, and partitions replicated across locations in certain intervals.

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PurchasingProduction

SalesPurchasingProduction

Sales

Purchasing Production

Sales

Toronto Vancouver

Winnipeg

• Computer networks – key role in distributed systems. Networks are part of IT Infrastructure (foundational systems serving entire enterprise).

Mainframe with dumb terminalsin departments

Departmentalstand-alone systems

Client-ServerSystems in/across

departments

Centralized Decentralized

• Data processing, data storage, user interface – a continuum showing levels of distribution of system parts in an enterprise:

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Distributed Systems Continuum

Client-Server (C/S) Architecture

• Most frequent today

• C/S systems distribute data, functionality or both between a machine that requests a service (client) and a machine that provides a service (server).

Client ServerRequest

Service

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• Division of responsibilities for data and functions, user interface usually on the client.

• Models of C/S architecture determined by different patterns of

sharing responsibility for data, functionality, and user interface

between computers.

Models of Client-Server Architecture

• Shared Processing (both server and client have certain functionality;

LAN w/ database server, Internet models – applets, Web services)

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Client - Input/Output screens- Query and Report code

Report creation Request

Report

Data lookup, input

Data table transfer

Note: Server is software, but it usually runs on a dedicated computer.

- Database (data)- Query and Report processing…

Database Sever

• Variant of Shared Processing with middleware

• * Example from HR domain: An employee is defined by an employee number, name, job position…, is associated with 1 department, reports to 1 manager, cannot have $0 salary, can have different benefit packages over time, etc.

Middleware

Database Server (Databases can be on a mainframe - “legacy system”)

(Code defining rules of business*; translation software)

Client (Applicationsoftware)

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• Variant of Shared Processing via the Internet (applets; Web services)

• Cases: SABRE

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- Upon getting data & applet, runsif-then calculations

Web Server

Application Server

Other systems

Mortgage InfoRequest Customer data

Customer Data +

Mortgage Applet

Client

Internet

Database ServerRequest

translated

Request

translatedWeb page

Web page with cust. data + applet

• Case: Chubb & Son

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Messages for Change Leadership

• If business is to get distributed, determine how can IS support this strategy.

• Be sensitive to company’s culture regarding its readiness for distributed systems (trust issues).

• Beware that data must be available where users need them, and that users should not worry whether the system is distributed or not.