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Systems Analysis and Design 8th EditionChapter 4Requirements Modeling1Phase DescriptionSystems analysis is the second of five phases in the systems development life cycle (SDLC)Will use requirements modeling, data and process modeling, and object modeling techniques to represent the new systemWill consider various development strategies for the new system, and plan for the transition to systems design tasks22Chapter Objectives Describe systems analysis phase activities and the end product of the systems analysis phaseExplain joint application development (JAD), rapid application development (RAD), and agile methodsUnderstand how systems analysts use a functional decomposition diagram (FDD)33Chapter ObjectivesDescribe the Unified Modeling Language (UML) and explain use case diagrams and sequence diagramsList and describe system requirements, including outputs, inputs, processes, performance, and controlsExplain the concept of scalability44Chapter ObjectivesUse fact-finding techniques, including interviews, documentation review, observation, questionnaires, sampling, and researchDefine total cost of ownership (TCO)Conduct a successful interviewDevelop effective documentation methods to use during systems development55IntroductionThis chapter describes requirements modeling techniques and team-based methods that systems analysts use to visualize and document new systemsThe chapter then discusses system requirements and fact-finding techniques, which include interviewing, documentation review, observation, surveys and questionnaires, sampling, and research66Systems Analysis Phase OverviewThe overall objective of the systems analysis phase is to understand the proposed project, ensure that it will support business requirements, and build a solid foundation for system developmentYou use models and other documentation tools to visualize and describe the proposed system77Systems Analysis Phase Overview

8Systems Analysis ActivitiesRequirements modelingOutputsInputsProcessesPerformanceSecurity

8Systems Analysis Phase OverviewSystems Analysis ActivitiesData and process modelingObject ModelingDevelopment StrategiesSystem requirements document

99Systems Analysis Phase OverviewSystems Analysis SkillsAnalytical skillsInterpersonal skillsTeam-Oriented Methods and TechniquesJoint application development (JAD)Rapid application development (RAD) Agile methods1010Joint Application Development (JAD)User InvolvementUsers have a vital stake in an information system and they should participate fullySuccessful systems must be user-oriented, and users need to be involvedOne popular strategy for user involvement is a JAD team approach1111Joint Application Development (JAD)JAD Participants and Roles12

12Joint Application Development (JAD)JAD Advantages and DisadvantagesMore expensive and can be cumbersome if the group is too large relative to the size of the projectAllows key users to participate effectively When properly used, JAD can result in a more accurate statement of system requirements, a better understanding of common goals, and a stronger commitment to the success of the new system1313Rapid Application Development (RAD)RAD Phases and Activities14

14Rapid Application Development (RAD)RAD ObjectivesTo cut development time and expense by involving the users in every phase of systems developmentSuccessful RAD team must have IT resources, skills, and management supportHelps a development team design a system that requires a highly interactive or complex user interface1515Rapid Application Development (RAD)RAD Advantages and DisadvantagesSystems can be developed more quickly with significant cost savingsRAD stresses the mechanics of the system itself and does not emphasize the companys strategic business needsMight allow less time to develop quality, consistency, and design standards1616Agile MethodsAttempt to develop a system incrementallyAgilian modeling toolset includes support for many modeling toolsSome agile developers prefer not to use CASE tools at all, and rely instead on whiteboard displays and arrangements of movable sticky notes

1717Agile MethodsAgile Method Advantages and DisadvantagesAre very flexible and efficient in dealing with changeFrequent deliverables constantly validate the project and reduce riskTeam members need a high level of technical and interpersonal skillsMay be subject to significant change in scope1818Modeling Tools and TechniquesCASE ToolsFunctional Decomposition Diagrams (FDD)Data Flow Diagrams (DFD)Unified Modeling Language (UML)1919System Requirements ChecklistOutputsThe Web site must report online volume statistics every four hours, and hourly during peak periodsThe inventory system must produce a daily report showing the part number, description, quantity on hand, quantity allocated, quantity available, and unit cost of all sorted by part number2020System Requirements ChecklistInputsManufacturing employees must swipe their ID cards into online data collection terminals that record labor costs and calculate production efficiencyThe department head must enter overtime hours on a separate screen2121System Requirements ChecklistProcessesThe student records system must calculate the GPA at the end of each semesterAs the final step in year-end processing, the payroll system must update employee salaries, bonuses, and benefits and produce tax data required by the IRS2222System Requirements ChecklistPerformanceThe system must support 25 users online simultaneouslyResponse time must not exceed four seconds2323System Requirements ChecklistControlsThe system must provide logon security at the operating system level and at the application levelAn employee record must be added, changed, or deleted only by a member of the human resources department2424Future Growth, Costs, and BenefitsScalabilityA scalable system offers a better return on the initial investmentTo evaluate scalability, you need information about projected future volume for all outputs, inputs, and processes2525Future Growth, Costs, and BenefitsTotal Cost of OwnershipTotal cost of ownership (TCO) is especially important if the development team is evaluating several alternativesOne problem is that cost estimates tend to understate indirect costs Rapid Economic Justification (REJ)26

26Fact-FindingFact-Finding OverviewFirst, you must identify the information you needDevelop a fact-finding planWho, What, Where, When, How, and Why?Difference between asking what is being done and what could or should be done2727Fact-Finding

28The Zachman FrameworkZachman Framework for Enterprise ArchitectureHelps managers and users understand the model and assures that overall business goals translate into successful IT projects

28InterviewsStep 1: Determine the People to InterviewInformal structuresStep 2: Establish Objectives for the InterviewDetermine the general areas to be discussedList the facts you want to gather29

29InterviewsStep 3: Develop Interview QuestionsCreating a standard list of interview questions helps to keep you on track and avoid unnecessary tangentsAvoid leading questionsOpen-ended questionsClosed-ended questionsRange-of-response questions3030InterviewsStep 4: Prepare for the InterviewCareful preparation is essential because an interview is an important meeting and not just a casual chatLimit the interview to no more than one hourSend a list of topicsAsk the interviewee to have samples available3131InterviewsStep 5: Conduct the InterviewDevelop a specific plan for the meetingBegin by introducing yourself, describing the project, and explaining your interview objectivesEngaged listeningAllow the person enough time to think about the questionAfter an interview, you should summarize the session and seek a confirmation3232InterviewsStep 6: Document the InterviewNote taking should be kept to a minimumAfter conducting the interview, you must record the information quicklyAfter the interview, send memo to the interviewee expressing your appreciationNote date, time, location, purpose of the interview, and the main points you discussed so the interviewee has a written summary and can offer additions or corrections3333InterviewsStep 7: Evaluate the InterviewIn addition to recording the facts obtained in an interview, try to identify any possible biasesUnsuccessful InterviewsNo matter how well you prepare for interviews, some are not successful3434Other Fact-Finding TechniquesDocument ReviewObservationSeeing the system in action gives you additional perspective and a better understanding of the system proceduresPlan your observations in advanceHawthorne Effect35

35Other Fact-Finding Techniques

36Questionnaires and SurveysWhen designing a questionnaire, the most important rule of all is to make sure that your questions collect the right data in a form that you can use to further your fact-findingFill-in form36Other Fact-Finding TechniquesSamplingSystematic sampleStratified sampleRandom sampleMain objective of a sample is to ensure that it represents the overall population accurately

3737Other Fact-Finding TechniquesResearchCan include the Internet, IT magazines, and books to obtain background information, technical material, and news about industry trends and developmentsSite visit38

38Other Fact-Finding TechniquesInterviews versus QuestionnairesInterview is more familiar and personalQuestionnaire gives many people the opportunity to provide input and suggestionsBrainstormingStructured brainstormingUnstructured brainstorming3939DocumentationThe Need for Recording the FactsRecord information as soon as you obtain itUse the simplest recording methodRecord your findings in such a way that they can be understood by someone elseOrganize your documentation so related material is located easily4040Documentation

41Software ToolsCASE ToolsProductivity SoftwareGraphics modeling softwarePersonal information managersWireless communication devices41Preview of Logical ModelingAt the conclusion of requirements modeling, systems developers should have a clear understanding of business processes and system requirementsThe next step is to construct a logical model of the systemIT professionals have differing views about systems development methodologies, and no universally accepted approach exists4242Chapter SummaryThe systems analysis phase includes three activities: requirements modeling, data and process modeling, and consideration of development strategiesThe main objective is to understand the proposed project, ensure that it will support business requirements, and build a solid foundation for the systems design phase4343Chapter SummaryThe fact-finding process includes interviewing, document review, observation, questionnaires, sampling, and researchSystems analysts should carefully record and document factual information as it is collected, and various software tools can help an analyst visualize and describe an information system

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