Chapter 10
Selecting the Best Alternative Design Strategy
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Topics
Sources of software
Generating design strategies
Selection strategy
Weighting/scoring alternatives
In-house development
COTS
Outsourcing
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System 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 Strategy
Divide requirements into sets of capabilities, categorized
by level of necessity:
Mandatory
Good to have
Wish list
Enumerate potential implementation environments:
Hardware and system software platforms
Consider different sourcing possibilities for obtaining the
necessary software:
In-house
Outsource
Consultants
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Generating a Design Strategy
Features are
determined from
requirements.
Constraints pertain to
limitations on
development efforts.
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Main Sources of Software
–
–
–
–
–
Hardware Manufacturers
Prepackaged Software Producers
Custom Software Producers
Enterprise Solutions Software
In-house Development
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In-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 inhouse staff playing a role as well as consultants or ERP
vendors
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Evaluating 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
 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
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Hardware 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 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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Off-the-shelf Software
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.
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Custom 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)
 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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Implementation Issues
Hardware 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
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Implementation Issues
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
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Example: 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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Weighted Scoring
Alternative C: Server/Object scores the highest
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Chosen alternative: 3-Tier architecture
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
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Baseline project plan
•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.
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