Kế toán, kiểm toán - Chapter 21: Ais development strategies

Chapter 21AIS Development StrategiesCopyright © 2012 Pearson Education21-1Learning ObjectivesDescribe how organizations purchase application software, vendor services, and hardware.Explain how information system departments develop custom software.Explain how end users develop, use, and control computer- based information systems.Explain why organizations outsource their information systems, and evaluate the benefits and risks of this strategy.Explain the principles and challenges of business process management.Describe how prototypes are used to develop an AIS, and discuss the advantages and disadvantages of doing so.Explain what computer-aided software engineering is and how it is used in systems development.Copyright © 2012 Pearson Education21-2Ways to Obtain an AISPurchase the softwareDevelop software in-houseHire and external company to develop and maintain new softwareCopyright © 2012 Pearson Education21-3Purchasing SoftwareOff the Shelf (OTS) CannedSystem capabilities for users with similar requirementsTurnkey SystemHardware and software sold as a packageApplication Service Provider (ASP)Software is provided to user via the InternetCopyright © 2012 Pearson Education21-4In-House System DevelopmentMain criteria for in-house developmentProvides a significant competitive advantageRisks of in-house developmentSignificant amounts of time requiredComplexity of the systemPoor requirements definedInsufficient planningInadequate communication and cooperationLack of qualified staffPoor top management supportCopyright © 2012 Pearson Education21-5End-User Computing (EUC)Hands-on development, use, and control of computer- based information systems by usersAdvantages of EUCUser creation, control, and implementationUsers decide whether a system should be developed and what information is important.Systems that meet user needsUsers discover flaws that IS people do not catch.Many of the user-analyst-programmer communication problems in traditional program development are avoided.TimelinessTime-consuming cost-benefit analyses, detailed requirements definitions, and the delays and red tape of the approval process can be avoided.Copyright © 2012 Pearson Education21-6End-User Computing (EUC) (cont’d)Advantages of EUC (cont’d)Freeing up of systems resourcesThe more information needs users meet, the more time the IS department can spend on other development and maintenance activities.Versatility and ease of useUsers can change the information they produce or modify their application any time their requirements change.Disadvantages to EUC:Logic and development errorsInadequately tested applicationsInefficient systemsPoorly controlled systemsPoorly documented systemsIncompatible systemsRedundant dataWasted resourcesIncreased costsCopyright © 2012 Pearson EducationOutsourcing the SystemHiring an outside company to handle all or part of an organization’s data processing activitiesAdvantages:Strategic and economic business solution that allows companies to concentrate on core competenciesOrganizations improve their cash position and reduce expenses by selling assets to an outsourcerAccess to greater expertise and better technologyLower costs by standardizing user applications, buying hardware at bulk prices, splitting development and maintenance costs between projects, and operating at higher volumesLess development time.Elimination of peaks-and-valleys Facilitates downsizingDisadvantages:InflexibilityReduced competitive advantageUnfulfilled goalsPoor serviceIncreased riskCopyright © 2012 Pearson Education21-8Methods to Develop an AISBusiness Process RedesignPrototypingComputer-Aided Software Engineering (CASE) ToolsCopyright © 2012 Pearson Education21-9Business Process RedesignDrastic, one-time-event approach to improving and automating business processesLow success rateEvolved into:Business Process Management (BPM)Systematic approach to continuously improving and optimizing an organization’s business processesCopyright © 2012 Pearson Education21-10PrototypingCopyright © 2012 Pearson Education21-11PrototypingAdvantagesBetter definition of user needsHigher user involvement and satisfactionFaster development timeFewer errorsMore opportunity for changesLess costlyDisadvantagesLess efficient use of system resourcesInadequate testing and documentationNegative behavioral reactionsNever-ending developmentCopyright © 2012 Pearson Education21-12Computer-Aided Software Engineering (CASE)Software to help plan, analyze, design, program, and maintain an information systemStrategic planningProject and system managementDatabase designScreen and report layoutAutomatic code generationCopyright © 2012 Pearson Education21-13CASE Advantages vs. DisadvantagesImproved productivityImproved program qualityCost savingsImproved control proceduresSimplified documentationIncompatibilityCostUnmet expectationsCopyright © 2012 Pearson Education21-14