1、信息時(shí)代的管理信息系統(tǒng)STUDENT LEARNING OUTCOMESDefine the traditional systems development life cycle (SDLC) and describe the 7 major phases within it.Compare and contrast the various component-based development methodologies.Describe the selfsourcing process as an alternative to the traditional SDLC.6-2STUDENT

2、 LEARNING OUTCOMESDiscuss the importance of prototyping and prototyping within any systems development methodologyDescribe the outsourcing environment and how outsourcing works.6-3SAVING LIVES THROUGH SYSTEMS DEVELOPMENTCenters for Disease Control (CDC) tracks a wealth of informationAntimicrobial-re

3、sistant infections in hospitalsInfluenza outbreaksTerrorist biochemical attacksBacteria counts in rivers and stagnant ponds, etcUnfortunately, most of that information is stored in separate IT systems that do not communicate with each other 6-4SAVING LIVES THROUGH SYSTEMS DEVELOPMENTThe CDC is using

4、 a service-oriented architecture (SoA) to integrate all those systems and informationAn SoA treats every component of an IT system a database file, a server, a CRM software solution, etc as a building blockWithin an SoA, those building blocks can be “plugged and played” so that everything works toge

5、ther in an integrated fashion6-5SAVING LIVES THROUGH SYSTEMS DEVELOPMENTAll computers use a common binary base language. That being true, why is it so difficult to get computer systems to easily communicate with each other?In systems development, prototyping is used to build a model of a proposed sy

6、stem. How have you used prototyping in your life?Outsourcing going to another company for systems development is big business. Why would the CDC not want to pursue outsourcing?6-6INTRODUCTIONInformation systems are the support structure for meeting the companys strategies and goalsNew systems are cr

7、eated because employees request themNew systems are created to obtain a competitive advantage6-7INTRODUCTIONWhen developing a new system, you have 3 “who” choicesInsourcing IT specialists inside your organizationSelfsourcing do-it-yourself approach many end users take with little or no help from IT

8、specialists1.Outsourcing a third-party organization (i.e., let someone do the work and pay them for it)6-8CHAPTER ORGANIZATIONInsourcing and the SDLCLearning outcome #1Component-Based DevelopmentLearning outcome #2SelfsourcingLearning outcome #3PrototypingLearning outcome #4OutsourcingLearning outco

9、me #56-9INSOURCING AND THE SDLCSystems development life cycle (SDLC) - a structured step-by-step approach for developing information systems 7 distinct phases, each with well-defined activitiesAlso called a waterfall methodology, an approach in which each phase of the SDLC is followed by another, fr

10、om planning through implementation6-10SDLC Phases & Major Activities6-11SDLC as a Waterfall Methodology6-12Phase 1: PlanningPlanning phase - create a solid plan for developing your information system Three primary planning activities:Define the system to be developedYou cant build every system,

11、so you make choices based on your organizations priorities, which may be expressed as critical success factors1.Critical success factor (CSF) - a factor simply critical to your organizations success 6-13Phase 1: PlanningSet the project scopeProject scope - clearly defines the high-level system requi

12、rements Scope creep - occurs when the scope of the project increasesFeature creep - occurs when developers add extra features that were not part of the initial requirements2.Project scope document - a written definition of the project scope and is usually no longer than a paragraph 6-14Phase 1: Plan

13、ningDevelop the project plan including tasks, resources, and timeframesProject plan - defines the what, when, and who questions of system developmentProject manager - an individual who is an expert in project planning and management, defines and develops the project plan and tracks the plan to ensur

14、e all key project milestones are completed on time3.Project milestones - represent key dates for which you need a certain group of activities performed 6-15Phase 1: Planning6-16Phase 2: AnalysisAnalysis phase - involves end users and IT specialists working together to gather, understand, and documen

15、t the business requirements for the proposed system 6-17Phase 2: AnalysisTwo primary analysis activities:Gather the business requirementsBusiness requirements - the detailed set of knowledge worker requests that the system must meet in order to be successfulBusiness requirements address the “why” an

16、d “what” of your development activities1.Joint application development (JAD) - knowledge workers and IT specialists meet, sometimes for several days, to define or review the business requirements for the system 6-18Phase 2: AnalysisPrioritize the requirementsRequirements definition document prioriti

17、zes the business requirements and places them in a formal comprehensive document Again, you probably cant do everything, so prioritizing is important2.Users sign off on this document which clearly sets the scope for the project6-19Phase 2: Analysis6-20Phase 3: DesignDesign phase - build a technical

18、blueprint of how the proposed system will work Two primary design activities:Design the technical architecture 1.Technical architecture - defines the hardware, software, and telecommunications equipment required to run the system 6-21Phase 3: DesignDesign system modelsThis includes GUI screens that

19、users will interface with, database designs (see XLM/C), report formats, software steps, etc2.Starting with design, you take on less of an active participation role and act more as a “quality control” function, ensuring that the IT people are designing a system to meet your needs6-22Phase 4: Develop

20、mentDevelopment phase - take all of your detailed design documents from the design phase and transform them into an actual system Two primary development activities:Build the technical architectureBuild the database and programs 1.Both of these activities are mostly performed by IT specialists6-23Ph

21、ase 5: TestingTesting phase - verifies that the system works and meets all of the business requirements defined in the analysis phase Two primary testing activities:Write the test conditions1.Test conditions - the detailed steps the system must perform along with the expected results of each step 6-

22、24Phase 5: TestingPerform the testing of the systemUnit testing tests individual units of codeSystem testing verifies that the units of code function correctly when integratedIntegration testing verifies that separate systems work together2.User acceptance testing (UAT) determines if the system sati

23、sfies the business requirements 6-25Phase 6: ImplementationImplementation phase - distribute the system to all of the knowledge workers and they begin using the system to perform their everyday jobs Two primary implementation activitiesWrite detailed user documentation1.User documentation - highligh

24、ts how to use the system 6-26Phase 6: ImplementationProvide training for the system usersOnline training - runs over the Internet or off a CD-ROM 2.Workshop training - is held in a classroom environment and lead by an instructor 6-27Phase 6: ImplementationChoose the right implementation methodParall

25、el implementation use both the old and new system simultaneouslyPlunge implementation discard the old system completely and use the new Pilot implementation start with small groups of people on the new system and gradually add more usersPhased implementation implement the new system in phases 6-28Ph

26、ase 7: Maintenance Maintenance phase - monitor and support the new system to ensure it continues to meet the business goals Two primary maintenance activities:Build a help desk to support the system users Help desk - a group of people who responds to knowledge workers questions Provide an environmen

27、t to support system changes 6-29COMPONENT-BASED DEVELOPMENTThe SDLC focuses only on the project at handComponent-based development (CBD) focuses on building small self-contained blocks of code (components) that can be reused across a variety of applicationsCBD focuses onUsing already-developed compo

28、nents to build systems quicklyBuilding new components as needed that can be used in all future systems6-30Component-Based Development MethodologiesRapid application development (RAD)Extreme programming (XP)Agile methodology 6-31Rapid Application Development (RAD) Rapid application development (RAD)

29、(also called rapid prototyping) - emphasizes extensive user involvement in the rapid and evolutionary construction of working prototypes of a system to accelerate the systems development processPrototypes are models of the software componentsThe development team continually designs, develops, and te

30、sts the component prototypes until they are finished6-32Rapid Application Development (RAD) 6-33Extreme Programming (XP) Extreme programming (XP) - breaks a project into tiny phases and developers cannot continue on to the next phase until the first phase is complete6-34Agile MethodologyAgile method

31、ology - a form of XP, aims for customer satisfaction through early and continuous delivery of useful software components 6-35SoA An Architecture PerspectiveService-oriented architecture (SoA) perspective that focuses on the development, use, and reuse of small self-contained blocks of code (called s

32、ervices) to meet all application software needsAll CBD methodologies adhere to an SoAServices are the same as components, which are the same as small self-contained blocks of codeMore in Chapter 76-36SELFSOURCINGSelfsourcing (end-user development) the development and support of IT systems by end use

33、rs with little or no help from IT specialistsDo-it-yourself systems development approachCan relieve IT specialists of the burden of developing many smaller systems6-37Selfsourcing ApproachIs similar to traditional SDLCBig exception is that design, development, testing, and implementation are replace

34、d by the process of prototypingPrototyping is the process of building models, and in this case continually refining those models until they become the final system6-38Selfsourcing Approach6-39Selfsourcing AdvantagesImproves requirements determinationIncreases end user participation and sense of owne

35、rshipIncreases speed of systems developmentReduces invisible backlogInvisible backlog list of all systems that an organization needs to develop but because of the prioritization of systems development needs never get funded because of the lack of organizational resources6-40Selfsourcing Disadvantage

36、sInadequate end user expertise leads to inadequately developed systemsLack of organizational focus creates “privatized” IT systemsInsufficient analysis of design alternatives leads to subpar IT systemsLack of documentation and external support leads to short-lived systems6-41The Right Tool for the J

37、ob End users must have development tools that:Are easy to useSupport multiple platformsOffer low cost of ownershipSupport a wide range of data types 6-42PROTOTYPINGPrototype a model of a proposed product, service, or systemPrototyping - the process of building a model that demonstrates the features

38、of a proposed product, service, or system Proof-of-concept prototype - used to prove the technical feasibility of a proposed systemSelling prototype - used to convince people of the worth of a proposed system 6-43The Prototyping Process The prototyping process involves four steps:Identify basic requ

39、irementsDevelop initial prototypeUser review1.Revise and enhance the prototype 6-44The Prototyping Process 6-45Advantages of Prototyping Encourages active user participation Helps resolve discrepancies among usersGives users a feel for the final systemHelps determine technical feasibility Helps sell

40、 the idea of a proposed system 6-46Disadvantages of Prototyping Leads people to believe the final system will followGives no indication of performance under operational conditionsLeads the project team to forgo proper testing and documentation 6-47OUTSOURCINGOutsourcing the delegation of specified w

41、ork to a third party for a specified length of time, at a specified cost, and at a specified level of serviceThe third “who” option of systems development, after insourcing and selfsourcing6-48OUTSOURCINGThe main reasons behind the rapid growth of the outsourcing industry include the following: Glob

42、alizationThe Internet Growing economy and low unemployment rateTechnology Deregulation 6-49Outsourcing OptionsIT outsourcing for software development can take one of four forms:Purchase existing softwarePurchase existing software and pay the publisher to make certain modificationsPurchase existing s

43、oftware and pay the publisher for the right to make modifications yourself1.Outsource the development of an entirely new and unique system for which no software exists 6-50Outsourcing Options6-51Outsourcing ProcessLike selfsourcing, the selfsourcing process looks similar to the traditional SDLCBig exception here is that you “outsource” most of the work to another company6-52Outsourcing Process6-53Outsourcing RFP Request for proposal (RFP) formal document that describes in excruc