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Chapter 6 Architecture and Infrastructure

Managing and Using Information Systems: A Strategic Approach, 2nd ed.

by Keri Pearlson and Carol Saunders

Copyright © 2003 John Wiley & Sons, Inc.

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omissions, or damages, caused by the use of these programs or from the use of the information contained herein.

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INTRODUCTION

• Chapter 6 examines the mechanisms by which business strategy is transformed into tangible information systems.

• The terms “architecture” and “infrastructure” are often used interchangeably, but here we discuss the differences as well as the role that each plays in realizing a business strategy.

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People’s Bank’s New 4-Tier Architecture

In 1998, PB decided it needed an architecture to:

• Tie together all its service delivery platforms back to a common set of business rules

• Create seamless links supporting real-time data transfer to its external partners

• Its new 4-tier architecture (next slide), implemented in stages, was up and running by Oct. 2000

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Figure 6.1 Architecture/Infrastructure of People’s Bank

The tier 3 servers and legacy systems communicate through message broker hub. Unisys mainframe runs core banking systems, while IBM S/390 runs general ledger, payroll and HR systems.

Legacy Systems

In the third tier, transaction processing control is built around IBM WebSphere Application Server, Enterprise Edition. The architecture is integrated with external data sources via TCP/IP sockets

Servers

In the second tier, IBM WebSphereApplication Server, Advanced Edition, serves as the Web application server.Web and

Application

The first (client) tier is composed of web browsers serving as the interface for customers and employees

Client

About InfrastructureInfrastructureArchitecture

People’s Bank

Customers

Call CenterRepre-

sentatives

Tellers atBranches

Tier 2 Web Servers

3rd PartyData Sources

Tier 3Web Servers

IBMS/390

Client ServerApplications

UnisysMainframe

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FROM VISION TO IMPLEMENTATION

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Architecture in construction

• IS architecture is like the architectural plans for a building, unchangeable in some areas, but subject to interpretation in others.

• Architectural plans are used by builders to select materials and use construction techniques based on past experience and industry standards.

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Translating Architecture into Infrastructure

• IT architecture provides a blueprint, translating business strategy into a plan for IS (see Figure 6.2).

• An IT infrastructure consists of physical components, chosen and assembled in a manner that best suits the plan…

• …and therefore best enables the overarching business strategy.

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Figure 6.2 Characteristics of popular

architectures Mainframe Client/

serverPeer-to-Peer

Wireless(Mobile)

Definition large, central computer handles all functionality

distributed computing environment

networked computers share resources

data connection from a remote network

Flexibility often proprietary; change difficult

Good Very good Good

Controls High; Low user control

Moderate user control

Based on TCP/IP; Good user control

Multiple standards; Good user control

Software Large set of exiting programs

Software harder to maintain; more likely to fail

Primarily used for sharing files, other resources

Heavily reliant on middleware

Scalability increasing in newer mainframes

Good because of modularity

Good; Well-suited for global systems

Very good

Security Easiest to maintain = centralization of data

Comparatively easy

Difficult because of wide distribution

Difficult because wireless network can be 'tapped"

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The Manager’s Role• The manager needs to communicate

with the IT architects and implementers to ensure that the resulting architecture meets the firm’s business strategy.

• Lack of managerial involvement can result in a poorly conceived, inefficient infrastructure that may even present obstacles to achieving business goals.

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THE LEAP FROM STRATEGY TO ARCHITECTURE TO

INFRASTRUCTURE

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From Strategy to Architecture• The manager’s role is to first set business

requirements for the desired IS (Figure 6.3).

• By outlining the firm’s overall business strategy, the manager makes sure the architecture will meet the firm’s business goals.

• Once it’s clear that the business requirements are being met, the next step is to translate the requirements into the IT architecture the system will use (Fig. 6.4).

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From Architecture to Infrastructure

• The next step is to translate architecture into infrastructure.

• This entails adding the actual hardware and software that will be used (Figure 6.5).

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Information System ComponentsInformation systems have 4 basic components:1. Hardware: physical components that handle

the computation, storage and transmission of data.

2. Software: programs that run on hardware and enable work to be performed

3. Network: hardware and software components connected according to a common protocol to create a shared computing environment.

4. Data: numbers and text that the IT infrastructure performs work on.

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A Framework for the translation (Figure 6.6a)

• The framework for translating business strategy into an IT architecture begins with a simple overview of the current IS components, asking “what, who and where” for each.

• For hardware, for example:• What hardware does the firm have?• Who manages, uses and owns it?• Where is it located? Where is it used?

• Similar questions apply to the software, network and data components of the system.

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Examples of Architectures

• Two examples of generic architectural styles are client/server and mainframe architectures.

• Client/Server architecture is an example of a type of architecture that is growing in use.

• Client/Server is modular so easy to add additional servers to a client/server architecture.

• Mainframe architecture has a central computer and is easier to manage in some ways because of this.

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OTHER MANAGERIAL CONSIDERATIONS

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Understanding existing architecture• Understanding existing architecture allows

managers to evaluate the IT requirements of an evolving business strategy vs. their current IT.

• Plans for the future architecture can then be compared with the current infrastructure to help identify which components of the current system can b e used in the system being developed.

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Relevant questions for managers:

• What IT architecture is already in place?

• Is the company developing the IT architecture from scratch?

• Is the company replacing an existing architecture?

• Does the company need to work within the confines of an existing architecture?

• Is the company expanding an existing architecture?

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Strategic IT planning and legacy systems

• Managers usually must deal with adapting existing architectures as part of planning their new systems.

• In so doing they encounter both:

– the opportunity to leverage the existing architecture and infrastructure and

– the challenge to overcome the old system’s shortcomings.

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Optimal conversion of legacy systems:• The following steps allow managers to

derive the most value and suffer the fewest problems when working with legacy systems:– 1. Objectively analyze the existing architecture

and infrastructure– 2. Objectively analyze the strategy served by

the existing architecture.– 3. Objectively analyze the ability of the existing

architecture and infrastructure to further the current strategic goals.

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Distinguishing Current vs. Future Requirements

• Strategic Time Frame

• Technological Advances

• Growth Requirements

• Assessing Financial Issues

• Differentiating Between Architecture and Infrastructure

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Steps in quantifying the return on infrastructure investments

1. Quantify costs2. Determine the anticipated life cycles

of system components3. Quantify benefits4. Quantify risks5. Consider ongoing dollar costs and

benefits

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ASSESSING TECHNICAL ISSUES

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Technical Issues to be considered

• Is the arch. or infrastructure scalable?• What is the company’s projected

growth?• Are there commonly-used standards?• How easy is the infrastructure to

maintain?• Do the IT staff have the skills to use

the components selected?

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Differentiating between Architecture and Infrastructure

• The Figure 6.8 shows the extent to which current and future requirements, associated financial issues, and technical criteria can be used to evaluate architecture and infrastructure.

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Figure 6.8 Applicability of evaluation criteria to discussion of architecture and

infrastructure Criteria Architecture Infrastructure

Strategic Time Frame

Very applicable Not applicable

Technological advances

Very applicable Somewhat applicable

Assessing financial issues:Net Present ValuePayback AnalysisIncidental Investments

Somewhat applicable

Very applicable

Growth requirements/ scalability

Very applicable Very applicable

Standardization Very applicable Very applicable

Maintainability Very applicable Very applicable

Staff experience Very applicable Very applicable

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Technological Advances

• IT architecture needs to be capable of supporting technological change

• At a minimum, the architecture should be able to handle expected technological advances

• An exceptional IT architecture will also have the ability to absorb unexpected technological leaps as well

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FROM STRATEGY TO ARCHITECTURE TO

INFRASTRUCTURE: AN EXAMPLE

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BluntCo. fictitious case• BluntCo., a fictitious cigar clipper maker,

serves to illustrate the process of creating IT architecture and infrastructure.

• The process includes four steps:

Step 1: Defining the Strategic Goals

Step 2: Define Related Architectural Goals

Step 3: Apply Strategy-to-Infrastructure Framework

Step 4: Evaluate Additional Issues

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Figure 6.10 BluntCo’s infrastructure

components Hardware Software Network Data 3 servers: •Sales

•Manufacturing

•Accounting

Storage systems

ERP system with modules for

•Manufacturing

•Sales

•Accounting

•Inventory

Enterprise Application Integration (EAI) software

Cable modem to ISPDial-up lines for backupRoutersHubsSwitchesFirewalls

Database: •Sales

•Manufacturing

•Accounting

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Step 1: Defining the Strategic Goals• Blunt Cos. business strategy is to respond to

possible changes in demand by outsourcing clipper manufacturing.

• The company’s strategic goals are as follows:– To lower costs by outsourcing manufacturing– To lower costs by clipper distribution– To improve market responsiveness by

outsourcing clipper manufacturing– To improve market responsiveness by

outsourcing clipper distribution

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Step 2: Define Related Architectural Goals

• Consider the first goal: outsourcing clipper manufacturing. How can the company’s IT architecture support this goal?

• It must provide the following interfaces to its new manufacturing partners:– Sales to manufacturing partners: send forecasts,

confirm orders received– Manufacturing partners to sales: send capacity,

confirm orders shipped– Manufacturing partners to accounting: confirm orders

shipped, electronic invoices, various inventory levels, returns

– Accounting to manufacturing partners: transfer funds for orders fulfilled

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Step 3: Apply Strategy to Infrastructure Framework

• Translating the strategic goals to the architectural and infrastructural framework means asking the what, who and where questions discussed before.

• For example, for the network:– Arch.: What is the anticipated volume of

transactions between BluntCo and its manufacturing partners?

– High volume may require leased lines to carry transaction data, dial-up connections may suffice for low volume (i.e., what’s the best leased line to use?).

• (see Fig. 6.7 for a detailed list of such questions.)

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Step 4: Evaluate Additional Issues

• The last step is to compare managerial considerations such as strategic time frame, technological advances, etc., with the architectural goals listed in step 2.

• For example, regarding HR compatibility:– Architecture: The new model will displace

some current human resources. BluntCo must analyze costs and the effect on morale.

– Infrastructure: Current staff not familiar with EDI; must be trained, some new staff hired. BluntCo must analyze associated costs.

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FOOD FOR THOUGHT: BUSINESS CONTINUITY

PLANNING

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Business Continuity Planning (BCP)• BCP is an approved set of preparations and

sufficient procedures for responding to a range of disaster events, such as:

1. Planning stage – alternative business recovery operating strategies are determined

2. Emergency Response Procedures – designed to prevent/limit injury to personnel on site, damage to structures/equipment and the degradation if vital business functions

3. Employee Awareness and Training Programs – must be well communicated throughout the organization

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END OF CHAPTER 6