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Chapter 10Chapter 10

Selecting the Best Alternative Design StrategySelecting the Best Alternative Design Strategy

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TopicsTopics

Sources of software

Generating design strategies

Selection strategy

Weighting/scoring alternatives

In-house development

COTS

Outsourcing

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System Design StrategySystem Design Strategy

Three strategies: •for high-functionality high-cost solution, •for minimum functionality low-cost solution, and •for middle-of-the-road

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Generating a Design StrategyGenerating a Design Strategy

Divide requirements into sets of capabilities, categorized by level of necessity:

MandatoryGood to have

Wish list

Enumerate potential implementation environments: Hardware and system software platforms

Consider different sourcing possibilities for obtaining the necessary software:

In-houseOutsourceConsultants

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Features are determined from requirements.

Constraints pertain to limitations on development efforts.

Generating a Design StrategyGenerating a Design Strategy

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Main Sources of SoftwareMain Sources of Software

– Hardware Manufacturers

– Prepackaged Software Producers

– Custom Software Producers

– Enterprise Solutions Software

– In-house Development

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In-house DevelopmentIn-house Development

If sufficient system development expertise with the chosen platform exists in-house, then some or all of the system can be developed by the organization’s own staff

Often, there are a variety of sources that are used, with in-house staff playing a role as well as consultants or ERP vendors

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Evaluating Purchased SoftwareEvaluating Purchased Software

Use a variety of information sources:

– Vendor’s proposal

– Running software through a series of tests

– Feedback from other users of the vendor’s product

– Independent software testing services

– Articles in trade publications

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Outsourcing is the practice of giving the responsibility for some or all of an organization’s information systems, applications and operations to an outside firm

Outsourcing can produce cost savings for the client, by leveraging the outsourcer’s economies of scale

OutsourcingOutsourcing

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Hardware ManufacturersHardware Manufacturers

IBM is the leader in software sales and services

Hardware manufacturers tend to focus on system software and utilities

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Prepackaged SoftwarePrepackaged Software

Microsoft is the leader in prepackaged software production.

Prepackaged software is commercial off-the-shelf software (COTS software)

Often, prepackaged software is turnkey software (i.e., not customizable) .

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Many factors go into selection of off-the-shelf software, many of which are relevant for other software purchases.

Vendor support and viability are always among the most important criteria.

Off-the-shelf Software

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Custom Software ProducersCustom Software Producers

Firms like Accenture and EDS are leading custom software producers.

Consulting firms that develop software to meet the client’s specific requirements

Consulting firms are usually called when the client company does not have in-house expertise or manpower available to develop the system.

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Enterprise Solutions Software

Enterprise Resource Planning (ERP) software – integrates individual traditional business functions modules enabling a single seamless transaction cut across functional boundaries

SAP AG is the leading vendor of ERP systems

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Request for Proposal (RFP) (RFP)

Request for Proposal – a document provided to vendors to ask them to propose hardware and/or software products or services that will meet the requirements of an organization’s new information system

Based on vendor bids, an organization selects the best candidates

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Hardware and System Software IssuesHardware and System Software Issues

Reasons to stay with old platform

– Lower cost installation

– Familiarity of IS staff

– Ease of integration with existing applications

– Less need for data and software conversions

Implementation Issues

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Hardware and System Software Issues (Continued)Hardware and System Software Issues (Continued)

Reasons to change to new platform

– New components may not be compatible with old platform

– New platform provides opportunity for organization to improve its technology holdings

– New platform serves as impetus for significant business process changes

Implementation Issues

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Example: Pine Valley FurnitureExample: Pine Valley Furniture

• System requirements categorized into mandatory, essential, and desired capabilities

• Constraints established

• Low-end, high-end, and moderate design strategies are generated and compared

• Weighted approach used to compare alternative design strategies

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Qualitative measures

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Alternative C: Server/Object scores the highest

Weighted Scoring

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3-Tier architecture is common: •a Web server providing the access via Internet - 1st tier

•an application server running the business rules - 2nd tier

•corporate databases - 3rd tier

Chosen alternative: 3-Tier architecture

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•BPP (from Ch 4 – see 92.2912) goes through significant update as a result of design strategy generation and selection.

•3.0.F updated for the analysis phase, and the next phases will be more detailed –Gantt charts

•The System Description section is changed the most, and all sections are refined and altered.

Baseline project plan