PHASE 2 : SYSTEM ANALYSIS*

PHASE DESCRIPTIONSystems analysis is the second of five phases in the systems development life cycle (SDLC)Uses requirements modeling and data and process modeling to represent the new system

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INTRODUCTIONThis 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 research

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SYSTEMS ANALYSIS PHASE OVERVIEWThe overall objective is to understand the proposed project, ensure that it will support business requirements, and build a solid foundation for system developmentYou use a models and other documentation tools to visualize and describe the proposed system

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SYSTEMS ANALYSIS PHASE OVERVIEWSystems Analysis ActivitiesRequirements modelingOutputsInputsProcessesPerformanceSecurity

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SYSTEMS ANALYSIS PHASE OVERVIEWSystems Analysis ActivitiesData and process modelingDevelopment StrategiesSystem requirements document

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SYSTEMS ANALYSIS PHASE OVERVIEWSystems Analysis SkillsAnalytical skillsInterpersonal skillsTeam-Oriented Methods and TechniquesJoint application development (JAD)Rapid application development (RAD)

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JOINT APPLICATION DEVELOPMENTUser 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 approach

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JOINT APPLICATION DEVELOPMENTJAD Participants and RolesJAD participants should be insulated from the distraction of day-to-day operationsObjective is to analyze the existing system, obtain user input and expectations, and document user requirements for the new system

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JOINT APPLICATION DEVELOPMENTJAD Advantages and DisadvantagesAdvantages Allows 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 systemDisadvantagesMore expensive and can be cumbersome if the group is too large relative to the size of the project

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RAPID APPLICATION DEVELOPMENTIs a team-based technique that speeds up information systems development and produces a functioning information systemRelies heavily on prototyping and user involvementProcess continues until the system is completely developed and users are satisfied

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RAPID APPLICATION DEVELOPMENTRAD Phases and Activities

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RAPID APPLICATION DEVELOPMENTRAD 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 interface

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RAPID APPLICATION DEVELOPMENTRAD Advantages and DisadvantagesAdvantagesSystems can be developed more quickly with significant cost savingsDisadvantagesRAD 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 standards

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MODELING TOOLS AND TECHNIQUESCASE ToolsFunctional Decomposition DiagramsAlso called structure charts

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MODELING TOOLS AND TECHNIQUESData Flow Diagrams

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MODELING TOOLS AND TECHNIQUESUnified Modeling LanguageWidely used method of visualizing and documenting software systems designUse case diagramsActorSequence diagramsSee http://www.developer.com/design/article.php/10925_2109801_1/Creating-Use-Case-Diagrams.htm

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SYSTEM REQUIREMENTS CHECKLISTSystem requirementFive general categoriesOutputsInputsProcessesPerformanceControls

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SYSTEM 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 number

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SYSTEM 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 screen

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SYSTEM 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 IRS

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SYSTEM REQUIREMENTS CHECKLISTPerformanceThe system must support 25 users online simultaneouslyResponse time must not exceed four seconds

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SYSTEM REQUIREMENTS CHECKLISTControlsThe system must provide log-on 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 department

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FUTURE GROWTH, COSTS, AND BENEFITSScalabilityA scalable system offers a better return on the initial investmentTo evaluate, you need information about projected future volume for all outputs, inputs, and processes

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FUTURE 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

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FACT-FINDINGFact-Finding OverviewThe first step is to 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 done

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

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INTERVIEWSSystems analysts spend a great deal of time talking with peopleMuch of that time is spent conducting interviews

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

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INTERVIEWSStep 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 questions

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INTERVIEWSStep 4: Prepare for the InterviewCareful preparation is essential because 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 available

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INTERVIEWSStep 5: Conduct the InterviewDevelop a specific plan for the meetingBegin by introducing yourself, describing the project, and explaining interview objectivesUse engaged listeningAllow the person enough time to think about the questionAfter interview, summarize the session and seek a confirmation

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INTERVIEWSStep 6: Document the InterviewNote taking should be kept to a minimumAfter the interview, record the information quicklyAfter the interview, send memo expressing appreciation, including the main points discussed so the interviewee has a written summary and can offer additions or corrections

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INTERVIEWSStep 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 successful

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OTHER FACT-FINDING TECHNIQUESDocument ReviewObservationSeeing the system in action gives you additional perspective and a better understanding of the system proceduresPlan your observations in advanceHawthorne Effect

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OTHER FACT-FINDING TECHNIQUESQuestionnaires 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 form

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OTHER FACT-FINDING TECHNIQUESSamplingSystematic sampleStratified sampleRandom sampleMain objective of a sample is to ensure that it represents the overall population accurately

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OTHER FACT-FINDING TECHNIQUESResearchCan include the Internet, IT magazines, and books to obtain background information, technical material, and news about industry trends and developmentsSite visit

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OTHER FACT-FINDING TECHNIQUESInterviews versus QuestionnairesInterview is more familiar and personalQuestionnaire gives many people the opportunity to provide input and suggestionsBrainstormingStructured brainstormingUnstructured brainstorming

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DOCUMENTATIONThe 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 easily

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DOCUMENTATIONSoftware ToolsCASE ToolsProductivity SoftwareWord processing, spreadsheets, database management, presentation graphics programsHistogram

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DOCUMENTATIONSoftware ToolsGraphics modeling softwarePersonal information managersPersonal information manager (PIM)Handheld computersPersonal digital assistants (PDAs)Wireless communication devices

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PREVIEW OF DATA AND PROCESS MODELINGAt the conclusion of requirements modeling, systems developers should have clear understanding of business processes and system requirementsThe next step is to model the logical design of the system

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CHAPTER 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 phase

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CHAPTER 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

Chapter 3 complete

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