Bài giảng Systems Analysis and Design - Chapter 10: Preparing the Systems Proposal

Preparing the Systems ProposalSystems Analysis and Design, 7eKendall & Kendall10© 2008 Pearson Prentice HallLearning ObjectivesInventory and appraise current and proposed hardware and software and the way it supports human interactions with technologyEvaluate software by addressing the trade-offs among creating custom software, purchasing COTS software, and outsourcing to an application service providerAssist decision makers in choosing decision support systems, including recommendation systems and neural nets2Learning Objectives (Continued)Forecast tangible and intangible costs and benefits, and perform a cost-benefit analysis using a number of methodsProfessionally write and present an effective systems proposal, incorporating figures and graphs3Systems ProposalA distillation of all that the system analyst has learned about users, the business, and about what is needed to improve its performanceSystematic methods to: Acquire hardware and softwareIdentify and forecast costs and benefitsPerform a cost-benefit analysis4Major TopicsAscertaining hardware/software needsTangible and intangible costs and benefitsSystems proposalUsing tables, graphs, and figures5Ascertaining Hardware and Software Needs Steps used to determine hardware and software needs:Inventory computer hardware currently availableEstimate current and future system workloadsEvaluate available hardware and software Choose the vendorAcquire the computer equipment6Figure 10.1 Steps in choosing hardware and software7Inventorying Computer HardwareType of equipmentOperation status of the equipmentEstimated age of equipmentProjected life of equipmentPhysical location of equipmentDepartment or person responsible for equipmentFinancial arrangement for equipment8Estimating WorkloadsSystems analysts formulate numbers that represent both current and projected workloads for the system so that any hardware obtained will possess the capability to handle current and future workloads9Figure 10.2 Comparisons of workloads between existing and proposed systems10Evaluating HardwareTime required for average transactionsTotal volume capacity of the systemIdle time of the CPU or networkSize of memory provided11People That Evaluate HardwareManagementUsersSystems analysts12Acquisition of Computer EquipmentBuyingLeasingRental13Buying14Leasing15Renting16Evaluating Vendor SupportHardware supportSoftware supportInstallation and training supportMaintenance support17Other ConsiderationsPossibility of adding on to the systemInterfacing with equipment from other vendorsAdding more memoryCorporate stability of the vendor18Software AlternativesCreated custom softwarePurchased as COTS (commercial off-the-shelf) softwareProvided by an application service provider (ASP)19Creating Custom Software20Purchasing COTS Packages21Using An ASP22Software EvaluationPerformance effectivenessPerformance efficiencyEase of useFlexibilityQuality of documentationManufacturer support23Figure 10.7 Guidelines for evaluating software24Decision Support ToolsAHP and other multiple-criteria softwareExpert systems and neural netsRecommendation systemsGetting external information from the Web25AHP and Other Multiple-criteria SoftwareMultiple-Criteria The objectiveAlternativesCriteriapriorityAHP compares all alternatives until all pairwise comparisons are made26Expert Systems and Neural NetsExpert systems are rule-based reasoning systems developed around an expert in the fieldNeural nets are developed by solving a number of problems of one type and letting the software get feedback on the decisions, observing what was involved in successful decisions27Recommendation SystemsSoftware and database systems that reduce the number of alternatives by ranking, counting, or some other methodDoes not depend on numeric weightsSimply counts the number of occurrences28Figure 10.9 Selected sources for external information available on the Web29Identifying and Forecasting Costs and BenefitsJudgment methodsEstimates from the sales forceSurveys to estimate customer demandDelphi studiesCreating scenariosDrawing historical analogies30Identifying and Forecasting Costs and Benefits (Continued)If historical data are availableConditionalThere is an association among variables in the modelUnconditionalDo not need to fine or identify any relationships31Estimation of TrendsGraphical judgmentThe method of least squaresMoving averages32Graphical JudgmentLooking at a graph and estimating by freehand an extension of a line or curveDisadvantageThe extension of the line may depend too much on individual judgmentAdvantageThe ability to perform what-if analysis33The Method of Least SquaresFind the best-fitting line by minimizing the sum of the deviations from the lineOnce the best-fitting line is found, it can be extended to forecast what will happen34Moving AveragesCalculate the arithmetic mean of data from groups or periods, then calculate the next arithmetic mean by discarding the oldest period’s data and adding the next periodAdvantageUseful for its smoothing abilityDisadvantageStrongly affected by extreme values35Figure 10.11 Calculating a five-year moving average36Identifying Benefits and CostsTangibleIntangible37Tangible BenefitsAdvantages measurable in dollars that accrue to the organization through the use of the information systemExamples:Increase in the speed of processingAccess to otherwise inaccessible informationAccess to information on a more timely basisThe advantage of the computer’s superior calculating powerDecreases in the amount of employee time needed to complete specific tasks38Intangible BenefitsIntangible benefits are benefits from use of the information system that are difficult to measureExamples:Improving the decision-making processEnhancing accuracyBecoming more competitive in customer serviceMaintaining a good business imageIncreasing job satisfaction39Tangible CostsThose that can be accurately projected by systems analysts and the business’ accounting personnelExamples:Cost of equipmentCost of resourcesCost of systems analysts' timeCost of programmers’ timeEmployees’ salaries40Intangible CostsThose that are difficult to estimate, and may not be knownExamples:Losing a competitive edgeLosing the reputation for being firstDeclining company imageIneffective decision making41Comparing Costs and BenefitsBreak-even analysisPaybackCash-flow analysisPresent value analysis42Break-Even AnalysisThe point at which the total cost of the current system and the proposed system intersectUseful when a business is growing and volume is a key variable in costsDisadvantageBenefits are assumed to remain the sameAdvantageCan determine how long it will take for the benefits of the system to pay back the costs of developing it43Figure 10.13 Break-even analysis showing a payback period of three and a half years44Cash-Flow AnalysisExamines the direction, size, and pattern of cash flow that is associated with the proposed information systemDetermine when cash outlays and revenues will occur for both not only for the initial purchase, but over the life of the information system45Figure 10.14 Cash-flow analysis for the computerized mail-addressing system46Present Value AnalysisWay to assess all the economic outlays and revenues of the information system over its economic life, and to compare costs today with future costs and today's benefits with future benefitsPresents the time value of the investment in the information system as well as the cash flow47Figure 10.16 Taking into account present value, the conclusion is that the costs are greater than the benefits. The discount rate, i, is assumed to be .12 in calculating the multipliers in this table48Guidelines for AnalysisUse break-even analysis if the project needs to be justified in terms of cost, not benefitsUse payback when the improved tangible benefits form a convincing argument for the proposed systemUse cash-flow analysis when the project is expensive, relative to the size of the companyUse present value when the payback period is long or when the cost of borrowing money is high49The Systems ProposalCover letterTitle page of projectTable of contentsExecutive summary Outline of systems study with appropriate documentationDetailed results of the systems studySystems alternatives Systems analysts recommendationsSummaryAppendices50Using Figures for Effective CommunicationEffective use of tablesEffective use of graphs51Effective Use of TablesIntegrate into the body of the proposalTry to fit the entire table vertically on a single pageNumber and title the table at the top of the pageLabel each row and columnUse a boxed table if room permitsUse footnotes if necessary to explain detailed information contained in the table52Figure 10.17 Guidelines for creating effective tables53Effective Use of GraphsChoose a style of graph that communicates your intended meaning wellIntegrate the graph into the body of the proposalGive the graph a sequential figure number and a meaningful titleLabel each axis, and any lines, columns, bars, or pieces of the pie on the graphInclude a key to indicate differently colored lines, shaded bars, or crosshatched areas54Types of GraphsLine graphsColumn chartsBar chartsPie charts55Line GraphsUsed to show change over timeChanges of up to five variables on a single graphMay also show when lines intersect56Figure 10.20 An area is a form of line graph that may make more of an impact57Column ChartsCan depict a comparison between two or more variables over timeUsed more often to compare different variables at a particular point in timeEasier to understand than line graphs58Figure 10.21 More then one variable can be displayed on a column Chart by shading or coloring the column bars59Special Forms of Column Charts100 percent stacked column chartShows the relationship between variables that makes up 100 percent of an entityDeviation Column ChartUseful for emphasizing years that show loss, or pointing out the year in which the company intends to break even60Bar ChartsUsed to show one or more variables within certain classes or categories during a specific time periodSorted or organizedAlphabeticalNumericalGeographicalProgressive orderMagnitude61Pie ChartsUsed to show how 100 percent of a commodity is divided at a particular point in timeEasier to read than 100 percent stacked column charts or 100 percent subdivided bar chartsDisadvantage is they take a lot of room on the page62Figure 10.24 A pie chart is a visually appealing way to display how 100 percent of an entity is divided up at a particular time63Presenting the Systems ProposalUnderstanding the audienceOrganizing the systems proposal presentationPrinciples of delivery64Understanding the AudienceHow formal to beWhat to presentWhat type of visual aids to include65Organizing the Systems Proposal PresentationIntroductionFour to six main points that capsulate the proposalConclusionQuestions66Principles of DeliveryProject your voice loudly enough so that the audience can hear youLook at each person in the audience as you speakMake visuals large enough so that the audience can see themUse gestures that are natural to your conversational styleIntroduce and conclude your talk confidently67SummaryComputer hardwarePurchaseLeaseRentalSoftwareCustomCOTSOutsourced68Summary (Continued)Decision support toolsMultiple-criteria decision makingExpert systemsNeural netsRecommendation systems69Summary (Continued)The systems proposalIdentifying costs and benefitsBreak-even analysisCash-flow analysisPresent value analysisPutting together an effective systems proposalVisual considerationsOral presentation70