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Systems Analysis and Design in a Changing World, Fifth Edition

Systems Analysis and Design in a Changing World, Fifth Edition. Learning Objectives. Describe the activities of systems analysis Explain the difference between functional and nonfunctional system requirements Describe three types of models and reasons for creating models

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Systems Analysis and Design in a Changing World, Fifth Edition

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  1. Systems Analysis and Design in a Changing World, Fifth Edition

  2. Systems Analysis and Design in a Changing World, 5th Edition Learning Objectives • Describe the activities of systems analysis • Explain the difference between functional and nonfunctional system requirements • Describe three types of models and reasons for creating models • Identify and understand the different types of users who will be involved in investigating system requirements

  3. Systems Analysis and Design in a Changing World, 5th Edition Learning Objectives (continued)‏ • Describe the kind of information that is required to develop system requirements • Determine system requirements through review of documentation, interviews, observation, prototypes, questionnaires, joint application design sessions, and vendor research • Discuss the need for validation of system requirements to ensure accuracy and completeness and the use of a structured walkthrough

  4. Systems Analysis and Design in a Changing World, 5th Edition Overview • Analysis phase of SDLC skills needed • Factfinding for investigation of systemrequirements • Analyst should learn details of businessprocesses and daily operations • Analyst should become as knowledgeableمطلع as business domain users to build credibility المصداقية • Analyst brings freshperspectiveوجهة نظر to problem • Modeling نمذجة of businessprocesses based on system requirements

  5. Systems Analysis and Design in a Changing World, 5th Edition The Analysis Phase in More Detail • Gatherinformation • Definesystemrequirements • Functional and nonfunctional • Prioritizerequirements • Prototype for feasibility and discovery • Generate and evaluatealternatives • Reviewrecommendations with management

  6. Systems Analysis and Design in a Changing World, 5th Edition The Activities of the Analysis Phase ‏ Figure 4-3

  7. Systems Analysis and Design in a Changing World, 5th Edition Activities of the Analysis Phase and Their Key Questions‏ Figure 4-2

  8. Systems Analysis and Design in a Changing World, 5th Edition System Requirements • Systemrequirements – specifications that define the newsystem • Functionalrequirements • Activitiessystemmustperform (usecases)‏ • Based on procedures and businessfunctions • Documented in analysismodels

  9. Systems Analysis and Design in a Changing World, 5th Edition System Requirements (cont)‏ • Nonfunctionalrequirements • Technical requirement – hardware and software • Performance requirement – workload measures • Usability requirement – userinterface, workflow • Reliability requirement – outages التوقف , errordetection • Security requirement – access & protection

  10. Systems Analysis and Design in a Changing World, 5th Edition Models and Modeling • Analystdescribesinformationsystemrequirements using a collection of models • Complexsystems require more than one type of model • Models represent some aspect سماتof the system being built • Process of creating models helps analyst clarify and refine design • Models assist communication with system users

  11. Systems Analysis and Design in a Changing World, 5th Edition Reasons for Modeling Figure 4-3

  12. Systems Analysis and Design in a Changing World, 5th Edition Types of Models • Different types of models are used in information systems development • Mathematical–formulas that describe technical aspects of the system • Descriptive– narrative memos, reports, or lists that describe aspects of the system • Graphical–diagrams and schematic representations of some aspect of the system

  13. Systems Analysis and Design in a Changing World, 5th Edition Some Descriptive Models Figure 4-4

  14. Systems Analysis and Design in a Changing World, 5th Edition Overview of Models Used in Analysis and Design • AnalysisModels named “define system requirements” • Logicalmodels • Provide detail without regard to specifictechnology • Designmodels • Physicalmodels • Provide technicaldetails • Extendlogicalmodels

  15. Systems Analysis and Design in a Changing World, 5th Edition Models Created During Analysis Figure 4-5

  16. Systems Analysis and Design in a Changing World, 5th Edition Stakeholders—The Source of SystemRequirements • People with interest in successfulsystemimplementation • Three primary groups of stakeholders • Users (use system)‏ • Clients (pay for and own system)‏ • Technicalstaff (Develop/Maintain system)‏ • Every type of stakeholder is identified by analyst

  17. Systems Analysis and Design in a Changing World, 5th Edition Stakeholders Interested in New System Development Figure 4-6

  18. Systems Analysis and Design in a Changing World, 5th Edition More On Users as Stakeholders • Horizontaluserroles–informationflowacrossdepartments • Verticaluserroles–informationneeds of clericalstaff, middlemanagement, and seniorexecutives • Businessusers perform day-to-day operations • Informationusers need current information • Managementusers need summary information • Executiveusers need strategic information • Externalusers may have access to system

  19. Systems Analysis and Design in a Changing World, 5th Edition RMO Stakeholders Figure 4-7

  20. Systems Analysis and Design in a Changing World, 5th Edition Techniques for Information Gathering • Analysis phase done to understandbusinessfunctions and developsystemrequirements • Original structured approach • Create model of existing system • Deriverequirements from existing system model • Current approach • Identify logicalrequirements for newsystem • Balance the review of currentbusinessfunctions with newsystemrequirements

  21. Systems Analysis and Design in a Changing World, 5th Edition Relationship Between Information Gathering and Model Building‏ Figure 4-8

  22. Systems Analysis and Design in a Changing World, 5th Edition Themesأفكار for Information-Gathering Questions Figure 4-9

  23. Systems Analysis and Design in a Changing World, 5th Edition Fact-Finding Methods • Reviewexistingreports, forms, and proceduredescriptions • Interview and discussprocesses with users • Observe and documentbusinessprocesses • Buildprototypes • Distribute and collectquestionnaires • Conduct joint application design (JAD) sessions • Researchvendorsolutions

  24. Systems Analysis and Design in a Changing World, 5th Edition Review Existing Reports, Forms, and Procedure Descriptions • Source: External industry-wide professional organizations and trade publications • Source: Existing business documents and procedure descriptions within organization • Identify business rules, discrepancies تعارضات , and redundancies • Be cautious of outdated material • Obtain preliminary understanding of processes • Use as guidelines/visualcues تلميحات to guide interviews

  25. Systems Analysis and Design in a Changing World, 5th Edition Sample Order Form for RMO‏ Figure 4-10

  26. Systems Analysis and Design in a Changing World, 5th Edition Conduct Interviews and Discussions with Users • Effective way to understand business functions and rules • Time consuming and resource expensive • May require multiple sessions to • Meet all users • Understand all processing requirements • Can meet with individuals or groups of users • List of detailed questions prepared

  27. Systems Analysis and Design in a Changing World, 5th Edition Sample Checklist to Prepare for User Interviews Figure 4-11

  28. Systems Analysis and Design in a Changing World, 5th Edition Sample Agenda for Interview Figure 4-12

  29. Systems Analysis and Design in a Changing World, 5th Edition A Sample Open-Items List Figure 4-13

  30. Systems Analysis and Design in a Changing World, 5th Edition Observe and Document Business Processes • Varies from office to performing actual tasks • Not necessary to observe all processes at same level of detail • May make users nervous, so use common sense • Can document workflows with UML activity diagrams

  31. Systems Analysis and Design in a Changing World, 5th Edition Activity Diagrams • Workflow – sequence of steps to process a businesstransaction • ActivityDiagram – workflowdiagram to describesequence of steps • Synchronizationbar – symbol to controlsplitting or merging of a path on an activitydiagram • Swimlane – boundedarea that containsactivities of a singleagent

  32. Systems Analysis and Design in a Changing World, 5th Edition Activity Diagram Symbols Figure 4-14

  33. Systems Analysis and Design in a Changing World, 5th Edition Activity Diagramthat Models a Workflow Figure 4-15

  34. Systems Analysis and Design in a Changing World, 5th Edition Activity Diagram with Concurrent Paths Figure 4-16

  35. Systems Analysis and Design in a Changing World, 5th Edition BuildPrototypes • Prototype - Preliminaryworkingmodel of a larger, more complex system component • Discovery, design, evolvingprototypes • Prototype should be • Operative • Working model to provide “look and feel” • Focused to accomplishsingleobjective • Quick • Built and modified rapidly with CASEtools

  36. Systems Analysis and Design in a Changing World, 5th Edition Distribute and Collect Questionnaires • Limited and specificinformation from a largenumber of stakeholders • Preliminary insight into business • Notwellsuited for gatheringdetailedinformation • Closed-endedquestionsdirectpersonansweringquestion • Open-endedquestionsencouragediscussion and elaboration

  37. Systems Analysis and Design in a Changing World, 5th Edition Sample RMO Questionnaire Figure 4-17

  38. Systems Analysis and Design in a Changing World, 5th Edition Conduct Joint Application Design Sessions • Expedites يعجلinvestigation of systemrequirements • Seeks to compressfact-finding, modeling, policyformation, and verificationactivities into shortertimeframe • Criticalfactor is to have allimportantstakeholderspresent

  39. Systems Analysis and Design in a Changing World, 5th Edition Joint Application Design Participants • Sessionleadertrained in groupdynamics and JADgroupfacilitation • Knowledgeablebusiness and systemusers and policymakers • Technicalstaff representatives to handle • Computer and network configurations • Operatingenvironments • Security issues • Projectteammembers

  40. Systems Analysis and Design in a Changing World, 5th Edition Joint Application Design Facilities • Conducted in specialroom • Limitinterruptions • May be off-site • Resources • Overhead projector, whiteboard, flipcharts, work material • Electronic support (laptops)‏ • CASEtools • Group support systems (GSS)‏

  41. Systems Analysis and Design in a Changing World, 5th Edition A JAD Facility Figure 4-18

  42. Systems Analysis and Design in a Changing World, 5th Edition Research Vendor Solutions • Many problems have been solved by other companies • Positivecontributions of vendor solutions • Frequently provide newideas • May be stateoftheart • Cheaper and less risky • Danger • May purchasesolutionbeforeunderstandingproblem

  43. Systems Analysis and Design in a Changing World, 5th Edition Useful Techniques in Vendor Research • Technicalspecificationsfromvendor • Demo or trial system • References of existingclients • On-sitevisits • Printout of screens and reports

  44. Systems Analysis and Design in a Changing World, 5th Edition Validating the Requirements • Make sure gathered information is correct • Structured walkthrough • Effective means of implementing quality control early in project • Verify and validate system requirements • Review of findings from investigation and of models based on findings • Project manager responsible for system quality • Systems analyst, project manager are partners

  45. Systems Analysis and Design in a Changing World, 5th Edition Structured Walkthrough Form Figure 4-19

  46. Systems Analysis and Design in a Changing World, 5th Edition Summary • Analysis phase activities • Gather information • Define system requirements • Prioritize requirements • Prototype for feasibility and discovery • Generate and evaluate alternatives • Review recommendations with management • BPR and Zachman Framework can help with the analysis phase activities

  47. Systems Analysis and Design in a Changing World, 5th Edition Summary (continued)‏ • Gathering system requirements • Functional and nonfunctional • Work with various stakeholders (users, clients, technical staff)‏ • What kind of information do I need? • What are the business processes and operations? • How are the business processes performed? • What are the information requirements?

  48. Systems Analysis and Design in a Changing World, 5th Edition Summary (continued)‏ • Primary information-gathering techniques • Review existing reports, forms, and procedure descriptions • Conduct interviews and discussions with users • Observe and document business processes • Build prototype working models • Distribute and collect questionnaires • Conduct JAD sessions • Research vendor solutions

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