Kế toán, kiểm toán - Chapter 20: Introduction to systems development and systems analysis

Chapter 20Introduction to Systems Development and Systems AnalysisCopyright © 2012 Pearson Education20-1Learning ObjectivesExplain the five phases of the systems development life cycle.Discuss the people involved in systems development and the roles they play.Explain the importance of systems development planning and describe planning techniques.Discuss the various types of feasibility analysis and calculate economic feasibility.Explain why system changes trigger behavioral reactions,What form this resistance to change takes, and how to avoid orminimize the resulting problems.Discuss the key issues and steps in systems analysis.Copyright © 2012 Pearson Education20-2Why Update Systems?User or business changesTechnology changesTo improve business processCreate competitive advantageIncrease productivity gainsIntegrate multiple systemsAging systems need replacementCopyright © 2012 Pearson Education20-3Software Development ProblemsMost software development projects deliver less, cost more, and take longer than expected.Standish Group found that:70 percent of software development projects were late54 percent were over budget66 percent were unsuccessful30 percent were canceled before completionAmerican Management Systems found that:75 percent of all large systems are not usedNot used as intended, orGenerate meaningless reports or inaccurate dataCopyright © 2012 Pearson Education20-4Systems Development Life Cycle (SDLC)Copyright © 2012 Pearson Education20-5SDLC StepsSystem AnalysisInformation about system needs, costs, and so on are gathered.Conceptual DesignGather system/user requirements.Physical DesignConcepts are translated into detailed specifications.Implementation and ConversionNew hardware and software are installed and tested.Employees are hired and trained or existing employees relocated.Processing procedures are tested and modified.Standards and controls for the new system are established and system documentation completed.Operation and MaintenanceNew system is periodically reviewed.Modifications are made as problems arise or as new needs become evident.Copyright © 2012 Pearson Education20-6Systems Analysis ActivitiesCopyright © 2012 Pearson Education20-7People Interacting in SDLCManagementAccountantsUsersInformation systems steering committeeProject development teamSystems analysts and programmersCopyright © 2012 Pearson Education20-8Planning SDLCProject Development PlanCost/benefit analysisDevelopmental and operational requirements (people, hardware, software, and financial)Schedule of the activities required to develop and operate the new applicationMaster PlanWhat the system will consist ofHow it will be developedWho will develop itHow needed resources will be acquiredWhere the AIS is headedCopyright © 2012 Pearson Education20-9Planning Technique—PERT ChartProgram Evaluation and Review Technique (PERT)Network of arrows and nodes representing project activities that require an expenditure of time and resources and the completion and initiation of activitiesCompletion time estimates madeCritical path—the path requiring the greatest amount of time is determinedCopyright © 2012 Pearson Education20-10Planning Technique—GANTT ChartA bar chart with project activities on the left-hand side and units of time across the topGraphically shows the entire schedule for a large, complex projectCopyright © 2012 Pearson Education20-11Feasibility AnalysisDoes it make sense to proceed with new system?Economic:Will system benefits justify the time, money, and resources required to implement it?Technical:Can the system be developed and implemented using existing technology?Legal:Does the system comply with all applicable federal and state laws, administrative agency regulations, and contractual obligations?SchedulingCan the system be developed and implemented in the time allotted?OperationalDoes the organization have access to people who can design, implement, and operate the proposed system? Will people use the system?Copyright © 2012 Pearson Education20-12Capital Budgeting: Economic FeasibilityCost-Benefit AnalysisBenefits and costs are estimated and compared to determine whether the system is cost beneficial.Benefits and costs that are not easily quantifiable are estimated and included.If they cannot be accurately estimated, they are listed, and their likelihood and expected impact on the organization evaluated.TechniquesPayback PeriodNumber of years required for the net savings to equal the initial cost of the investment.Net Present Value (NPV)Future benefits are discounted back to the present.Initial cost is subtracted.Positive NPV = economically feasible.Internal Rate of Return (IRR)The effective interest rate that results in an NPV of zero. A project’s IRR is compared with a minimum acceptable rate to determine acceptance or rejection. Copyright © 2012 Pearson Education20-13System Failure Due to ChangeThe best system will fail without the support of the people it serves.Why people resist change:FearLack of top management supportLack of communicationDisruptive nature of changeMethods of instituting changeBiases and emotionsPersonal characteristics and backgroundCopyright © 2012 Pearson Education20-14Types of ResistanceAggressionBehavior that destroys, cripples, or weakens system effectiveness, such as increased error rates, disruptions, or deliberate sabotageProjectionBlaming the new system for everything that goes wrongAvoidanceIgnoring a new AIS in the hope that the problem (the system) will eventually go awayCopyright © 2012 Pearson Education20-15Preventing ResistanceObtain management supportMeet user needsInvolve usersStress new opportunitiesAvoid being too emotionalProvide user trainingReexamine performance evaluation to make sure they are aligned with new systemKeep communication lines openControl users expectationsCopyright © 2012 Pearson Education20-16