R McFadyen Chapter 10 Selecting the Best Alternative Design Strategy

R McFadyen Topics Sources of software Generating design strategies Selection strategy Weighting/scoring alternatives In-house development COTS Outsourcing

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R McFadyen System Design Strategy Three strategies: for high-functionality high-cost solution, for minimum functionality low-cost solution, and for middle-of-the-road

R McFadyen 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

R McFadyen Features are determined from requirements. Constraints pertain to limitations on development efforts. Generating a Design Strategy

R McFadyen Main Sources of Software –Hardware Manufacturers –Prepackaged Software Producers –Custom Software Producers –Enterprise Solutions Software –In-house Development

R McFadyen 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 in- house staff playing a role as well as consultants or ERP vendors

R McFadyen 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

R McFadyen 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 Outsourcing

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R McFadyen Hardware Manufacturers IBM is the leader in software sales and services Hardware manufacturers tend to focus on system software and utilities

R McFadyen 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).

R McFadyen 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

R McFadyen 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.

R McFadyen 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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R McFadyen (RFP) 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

R McFadyen 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 Implementation Issues

R McFadyen 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

R McFadyen 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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R McFadyen Qualitative measures

R McFadyen Alternative C: Server/Object scores the highest Weighted Scoring

R McFadyen Tier architecture is common: a Web server providing the access via Internet - 1 st tier an application server running the business rules - 2 nd tier corporate databases - 3 rd tier Chosen alternative: 3-Tier architecture

R McFadyen BPP (from Ch 4 – see ) 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