Managing the development and purchase of information systems (Part 1)LEARNING GOALSSystems Development Methodology?QuestionsTraditional Systems Development Life Cycle (SDLC)QuestionPlanningSystems AnalysisSlide 9Data Flow Diagrams (DFD)Exercise 1: DFDExercise 2: DFDSystems DesignSystems Design toolsDevelopmentDevelopment toolsTestingImplementationMaintenanceProblems with Traditional SDLCSummary Questions1Managing the development and purchase of information systems (Part 1)BUS3500 - Abdou Illia, Spring 2007(Week 14, Thursday 4/12/2007)2LEARNING GOALSExplain the purpose of systems development methodologies.Describe the major phases of the traditional systems development life cycle (SDLC) metodology.3Systems Development Methodology?The process companies go through to develop and maintain an information systemFramework for successful IS developmentA System Development Methodology is usedFor building a new systemOr for modifying an existing systemExamples of SDM:System Development Life Cycle ￭ PrototypingJoint Application Development ￭ Rapid Application Development4QuestionsWhich of the following is true about SDM?1) They provide guidelines for developing IS and maintaining them which includes upgrading and improving them.2) SDM are needed when a brand new IS has to be developed, but you don’t need to use a SDM when it comes to modifying an existing IS.3) When a company is engaged in developing an IS, the process involves the company’s employees who would be the future users of the IS, and IS professionals like system analysts and programmers. But it doesn’t involve the company’s management4) All of the above5Traditional Systems Development Life Cycle (SDLC)Seven phases 1) Planning 5) Testing2) Systems Analysis 6) Implementation3) Systems Design 7) Maintenance4) DevelopmentTypically one phase needs to be completed before beginning the nextProblem in later phase may require return to previous phasePlanningAnalysisDesignDevelopmentTestingImplementationMaintenance6QuestionIn SDLC, the 7 phases are typically followed in a sequential order, which means we don’t return to a previous phase in any circumstances True False7PlanningFeasibility analysesTechnical AnalysisDo the technologies exist to develop the system?Economic AnalysisCan the organization afford the system?Will it provide an adequate Benefit?Operational Analysis (i.e. assessing the human element of the proposed system)Resistance to changeOrganizational politicsSystem development schedule Is the proposed development time line realistic?Is the programming team available during Programming step?Planning performed by Project Manager usingSearch and investigation (in for technical analysis step)Total Cost of Ownership analysisProject Management softwareFeasibility AnalysesSystem Development Schedule8Systems AnalysisSystems analyst works with company to understand the problem fully and to detail the requirements of the proposed systemStep 1: Analyze current systemObjectives:Understand what things are done and how (business processes)Identify any problems associated w/ current business processesTechniques:Observe employees at workTalk to employees (potential users)Analyze current systemDefine new system requirement9Systems AnalysisStep 2: Define new system’s requirementsObjectives:Specify What need to be done (not how to do it)To be defined:Input requirements (nature of data, source, etc.)Processing requirementsOutput requirements (Types of reports, content, etc.)Storage requirementsTools and techniquesData flow diagrams (DFD)Start with high level processAdd more levels with increased levels of detailComputer-Aided Software Engineering (CASE) toolsSoftware that eases the systems development processAnalyze current systemDefine new system requirements10Data Flow Diagrams (DFD)Data flowProcessExternal EntityData storageShows data being passed from or to a processAction that transform or manipulate dataSomething (person, group, department, etc.) outside the system that interact with the system by providing or receiving dataUsed to store data in the system. Represents a file, a database, etc.11Exercise 1: DFDUse Data Flow Diagram to illustrate your school’s registration system. Assume that Students are external entities. Also assume that there are three processes involved in course registration are:Verify Course availability after receiving a course request from a student. This involve checking the Course fileEnroll the student in the course after verifying course availabilityConfirm registration by sending a confirmation letter to student12Exercise 2: DFDDo the Lincoln Pizza’s ordering system DFD exercise available at:http://www.eiu.edu/~a_illia/BUS3500/DFD-Exercise.htm13Systems DesignUsing the requirements from Systems Analysis phase to design the new or modified system.Logical systems designDetails the system’s functionality (what it should do?)Uses Structure charts to create top-down representation of system’s modulesUses System flowcharts to show relationships between modulesPhysical systems designSpecifies all of the actual components (hardware, network, etc) used to implement the logical designDesign frozen at end of this phaseScope creepFeature creepPerformed by system designer or (system analyst in some case)14Systems Design toolsSALESDATAWEEKLYSALESPROGRAMWEEKLYSALES REPORTPAYROLLPROGRAMPAYCHECKSPAYROLLSUMMARYREPORTPAYROLLEXCEPTIONREPORTModule 1Module 2System Flowchart:Graphical representation of all programs within the system and how they interrelateProcess Pizza OrderOrder EntryPayment ProcessingInventoryManagementDeliveryStructure charts15DevelopmentProgramming process is usually the most difficult and time consuming in the Development process. Development performed by programmers, database developers, and network engineersProgrammers use Program Development Cycle1) Review the input, processing, output, and storage requirements2) Develop the logic of the programs (using Flowcharts and Pseudo code)3) Write the programs using code generators & programming languages4) Test and debug the programs5) Complete the programs documentation16Development toolsProgram Flowchart:Graphical illustration of the problem-solving logic within a programPseudocode:English-language statements that