Bài giảng Systems Analysis and Design - Chapter 1: Assuming the Role of the Systems Analyst

Summary Information is a key resource Systems analysts deal with many types of information systems Integration of traditional systems with new technologies Roles and qualities of the systems analyst The systems Development Life Cycle CASE tools Alternatives to structured analysis and design and to the SDLC

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Assuming the Role of the Systems AnalystSystems Analysis and Design, 7eKendall & Kendall1Kendall & Kendall1-*Learning ObjectivesRecall the basic types of computer-based systems that a systems analyst needs to addressUnderstand how users working in context with new technologies change the dynamics of a systemRealize what the many roles of the systems analyst areKnow the steps of the SDLC as they relate to HCI and how to apply them to a real systemUnderstand what CASE tools are and how they help a systems analystExplore other methodologies such as object-oriented systems design and prototypingKendall & Kendall1-*Information – A Key ResourceFuels business and can be the critical factor in determining the success or failure of a businessNeeds to be managed correctlyManaging computer-generated information differs from handling manually produced dataKendall & Kendall1-*Major TopicsFundamentals of different kinds of information systemsRoles of systems analystsPhases in the systems development life cycle as they relate to Human-Computer Interaction (HCI) factorsComputer-Aided Software Engineering (CASE) toolsKendall & Kendall1-*Systems Analysts Recommend, Design, and Maintain Many Types of Systems for UsersTransaction Processing Systems (TPS)Office Automation Systems (OAS)Knowledge Work Systems (KWS)Management Information Systems (MIS)Decision Support Systems (DSS)Expert Systems (ES)Executive Support Systems (ESS)Group Decision Support Systems (GDSS)Computer-Supported Collaborative Work Systems (CSCWS)Kendall & Kendall1-*Strategic LevelOperational LevelKnowledge LevelHigher LevelA systems analyst may be involved with any or all of these systems at each organization levelKendall & Kendall1-*Operational LevelTransaction Processing System (TPS)Process large amounts of data for routine business transactionsBoundary-spanningSupport the day-to-day operations of the companyExamples: Payroll Processing, Inventory ManagementKendall & Kendall1-*Knowledge LevelOffice Automation System (OAS)Supports data workers who share information, but do not usually create new knowledgeExamples: Word processing, Spreadsheets, Desktop publishing, Electronic scheduling, Communication through voice mail, Email, Video conferencingKnowledge Work System (KWS)Supports professional workers such as scientists, engineers, and doctorsExamples: computer-aided design systems, virtual reality systems, investment workstationsKendall & Kendall1-*Higher LevelManagement Information System (MIS)Support a broad spectrum of organizational tasks including decision analysis and decision makingExamples: profit margin by sales region, expenses vs. budgetsDecision Support System (DSS)Aids decision makers in the making of decisionsExamples: financial planning with what-if analysis, budgeting with modelingExpert System (ES)Captures and uses the knowledge of an expert for solving a particular problem which leads to a conclusion or recommendationExamples: MYCIN, XCONKendall & Kendall1-*Strategic LevelExecutive Support System (ESS)Helps executives to make unstructured strategic decisions in an informed wayExamples: drill-down analysis, status accessGroup Decision Support System (GDSS)Permit group members to interact with electronic supportExamples: email, Lotus NotesComputer-Supported Collaborative Work System (CSCWS)CDCWS is a more general term of GDSSMay include software support called “groupware” for team collaboration via network computersExample: video conferencing, Web survey systemKendall & Kendall1-*Integrating New Technologies into Traditional Systems Ecommerce and Web SystemsEnterprise Resource Planning SystemsWireless SystemsOpen Source SoftwareNeed for Systems Analysis and DesignKendall & Kendall1-*Figure 1.2 Systems analysts need to be aware that integrating technologies affects all types of systemsKendall & Kendall1-*Ecommerce and Web SystemsBenefitsIncreasing user awareness of the availability of a service, product, industry, person, or groupThe possibility of 24-hour access for usersImproving the usefulness and usability of interface designCreating a system that can extend globally rather than remain local, thus reaching people in remote locations without worry of the time zone in which they are locatedKendall & Kendall1-*Enterprise Resource Planning Systems (ERP)Performs integration of many information systems existing on different management levels and within different functionsExample: SAP, OracleKendall & Kendall1-*Wireless SystemsSystem analyst may be asked to design standard or wireless communication networks that integrate voice, video and email into organizational intranets or industry extranetsSystem analyst may also be asked to develop intelligent agentsExample: Microsoft's new software based on Bayesian statistics Wireless communication is referred as m-commerce (mobile commerce)Kendall & Kendall1-*Open Source SoftwareAn alternative of traditional software development where proprietary code is hidden from the usersOpen source software is free to distribute, share and modifyCharacterized as a philosophy rather than simply the process of creating new softwareExample: Linux Operating System, Apache Web Server, Mozilla Firefox Web browserKendall & Kendall1-*Need for Systems Analysis and DesignInstalling a system without proper planning leads to great user dissatisfaction and frequently causes the system to fall into disuseLends structure to the analysis and design of information systemsA series of processes systematically undertaken to improve a business through the use of computerized information systemsKendall & Kendall1-*Roles of the Systems AnalystThe analyst must be able to work with people of all descriptions and be experienced in working with computersThree primary roles:ConsultantSupporting ExpertAgent of changeKendall & Kendall1-*Qualities of the Systems AnalystProblem solverCommunicatorStrong personal and professional ethicsSelf-disciplined and self-motivated1-*Trần Quang – ĐHBK Tp.HCMKendall & Kendall1-*Systems Development Life Cycle (SDLC)The systems development life cycle is a phased approach to solving business problemsDeveloped through the use of a specific cycle of analyst and user activitiesEach phase has unique user activitiesKendall & Kendall1-*Figure 1.3 The seven phases of the systems development life cycleKendall & Kendall1-*Incorporating Human-Computer Interaction (HCI) ConsiderationsThe demand for analysts who are capable of incorporating HCI into the systems development process keeps increasing, as companies begin to realize that the quality of systems and the quality of work life can be improved by taking a human-centered approach at the outset of a projectKendall & Kendall1-*Identifying Problems, Opportunities, and ObjectivesActivity:Interviewing user managementSummarizing the knowledge obtainedEstimating the scope of the projectDocumenting the resultsOutput: Feasibility report containing problem definition and objective summaries from which management can make a decision on whether to proceed with the proposed projectKendall & Kendall1-*Determining Human Information RequirementsActivity:InterviewingSampling and investing hard dataQuestionnairesObserve the decision maker’s behavior and environmentPrototypingLearn the who, what, where, when, how, and why of the current systemOutput: Analyst understands how users accomplish their work when interacting with a computer; and begin to know how to make the new system more useful and usable. The analyst should also know the business functions and have complete information on the people, goals, data and procedure involvedKendall & Kendall1-*Analyzing System NeedsActivity:Create data flow diagrams Complete the data dictionaryAnalyze the structured decisions madePrepare and present the system proposalOutput: Recommendation on what, if anything, should be doneKendall & Kendall1-*Designing the Recommended SystemActivity:Design procedures for data entryDesign the human-computer interfaceDesign system controlsDesign files and/or databaseDesign backup proceduresOutputModel of the actual system Kendall & Kendall1-*Developing and Documenting SoftwareActivity:System analyst works with programmers to develop any original softwareWorks with users to develop effective documentationProgrammers design, code, and remove syntactical errors from computer programsDocument software with help files, procedure manuals, and Web sites with Frequently Asked QuestionsOutput:Computer programsSystem documentationKendall & Kendall1-*Testing and Maintaining the SystemActivity:Test the information systemSystem maintenance Maintenance documentationOutput:Problems, if anyUpdated programsDocumentationKendall & Kendall1-*Implementing and Evaluating the SystemActivity:Train usersAnalyst plans smooth conversion from old system to new systemReview and evaluate systemOutput:Trained personnelInstalled systemKendall & Kendall1-*Figure 1.4 Some researchers estimate that the amount of time spent on systems maintenance may be as much as 60 percent of the total time spent on systems projectsKendall & Kendall1-*The Impact of MaintenanceMaintenance is performed for two reasons Removing software errors, andEnhancing existing softwareOver time the cost of continued maintenance will be greater than that of creating an entirely new system. At that point it becomes more feasible to perform a new systems study Kendall & Kendall1-*Figure 1.5 Resource consumption over the system lifeKendall & Kendall1-*Approaches to Structured Analysis and Design and to the Systems Development Life CycleTraditional systems development life cycleCASE systems development life cycle Object-Oriented Systems Analysis and DesignKendall & Kendall1-*Case ToolsCASE tools are productivity tools for systems analysts that have been created explicitly to improve their routine work through the use of automated supportReasons for using CASE toolsIncreasing Analyst ProductivityImproving Analyst-User CommunicationIntegrating Life Cycle ActivitiesAccurately Assessing Maintenance ChangesKendall & Kendall1-*Case Tool ClassificationsUpper CASE tools perform analysis and designLower CASE tools generate programs from CASE designIntegrated CASE tools perform both upper and lower CASE functionsKendall & Kendall1-*Upper CASE ToolsCreate and modify the system designHelp in modeling organizational requirements and defining system boundariesCan also support prototyping of screen and report designsKendall & Kendall1-*Lower CASE ToolsLower CASE tools generate computer source code from the CASE designSource code is usually generated in several languagesKendall & Kendall1-*Figure 1.7 Traditional versus CASE systems development life cycleKendall & Kendall1-*Object-Oriented Systems Analysis and DesignAlternate approach to the structured approach of the SDLC that is intended to facilitate the development of systems that must change rapidly in response to dynamic business environmentsAnalysis is performed on a small part of the system followed by design and implementation. The cycle repeats with analysis, design and implementation of the next part and this repeats until the project is completeKendall & Kendall1-*Alternate Approaches to Structured Analysis and Design and to the Systems Development Life CycleAgile approachPrototypingETHICSProject championSoft Systems MethodologyMultiviewKendall & Kendall1-*SummaryInformation is a key resourceSystems analysts deal with many types of information systemsIntegration of traditional systems with new technologiesRoles and qualities of the systems analystThe systems Development Life CycleCASE toolsAlternatives to structured analysis and design and to the SDLC

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