Chapter 1Assuming the Role of theSystems Analyst     Systems Analysis and DesignMELJUN CORTES
Major Topics •   Information systems •   Phases of analysis and design •   System maintenance •   CASE tools •   Alternate...
Information • Information is an organizational     resource, which must be managed as     carefully as other resources. • ...
Categories   Information systems fall into one of the   following eight categories:       •    Transaction processing syst...
New Technologies   New technologies are being integrated   into traditional systems:       • Ecommerce uses the Web to per...
Kendall &   2005 PearsonKendall     Prentice Hall   1-6
Advantages of Using the Web • The benefits of using the Web are: • Increasing awareness of the availability     of the ser...
Nature of Analysis and Design   Systems analysis and design is a   systematic approach to:    • Identifying problems, oppo...
Systems Analyst • Systems analysts act as:     • Outside consultants to businesses.     • Supporting experts within a busi...
Systems Development LifeCycle • The systems development life cycle is a     systematic approach to solving     business pr...
Kendall &   2005 PearsonKendall     Prentice Hall   1-11
Phase 1 • Identifying:    • Problems.    • Opportunities.    • Objectives. • Personnel involved:    • Analyst.    • User m...
Phase 2 • Determining information requirements:    •   Interview management, operations personnel.    •   Gather systems/o...
Phase 2 (Continued) • Personnel involved:    • Analyst.    • User management.    • User operations workers.    • Systems m...
Phase 3 • Analyzing system needs:    • Create data flow diagrams.    • Document procedural logic for data flow diagram    ...
Phase 3 (Continued) • Personnel involved:    • Analyst.    • User management.    • Systems management.Kendall &    2005 Pe...
Phase 4 • Designing the recommended system:    • Design the user interface.       • Design output.       • Design input.  ...
Phase 4 (Continued) • Personnel involved:    • Analyst.    • System designer.    • User management.    • User operations w...
Phase 5 • Developing and documenting software:    • Design computer programs using structure        charts, Nassi-Schneide...
Phase 5 (Continued) • Personnel involved:    • Analyst.    • System designer.    • Programmers.    • Systems management.Ke...
Phase 6 • Testing and maintaining the system:    • Test and debug computer programs.    • Test the computer system.    • E...
Phase 6 (Continued) • Personnel involved:    • Analyst.    • System designer.    • Programmers.    • Systems management.Ke...
Phase 7 • Implementing and evaluating the    system:    • Plan conversion.    • Train users.    • Purchase and install new...
Phase 7 (Continued) • Personnel involved:    • Analyst.    • System designer.    • Programmers.    • User management.    •...
Rapid ApplicationDevelopment   Rapid Application development (RAD) is   an object-oriented approach to systems   developme...
System Maintenance • System maintenance is:    • Removing undetected errors, and    • Enhancing existing software. • Time ...
Kendall &   2005 PearsonKendall     Prentice Hall   1-27
System Enhancements   Systems are enhanced for the following   reasons:    • Adding additional features to the system.    ...
Kendall &   2005 PearsonKendall     Prentice Hall   1-29
CASE Tools     • CASE tools are automated,         microcomputer-based software packages         for systems analysis and ...
CASE Tool Categories    CASE tools may be divided into several    categories    • Upper CASE (also called front-end CASE) ...
Upper CASE    Upper CASE tools:    • Create and modify the system design.    • Store data in a project repository.    • Th...
Lower CASE • Lower CASE tools generate computer     source code from the CASE design. •   Source code may usually be gener...
Advantages of GeneratingCode      • Time to develop new systems decreases.      • The time to maintain generated code is l...
Kendall &   2005 PearsonKendall     Prentice Hall   1-35
Reverse Engineering • Reverse engineering is generating the     CASE design from computer program     code. •   Source cod...
Reverse Engineering(Continued) • Reverse engineering produces    (depending on the tool set used):    • Data structures an...
Advantages of ReverseEngineering    Reverse Engineering has the following    advantages:     • Reduced system maintenance ...
Object-Oriented Analysis andDesign • Object-oriented (O-O) analysis and     design is used to build object-oriented     pr...
The Unified ModelingLanguage • The Unified Modeling Language (UML)     is an industry standard for modeling     object-ori...
Extreme Programming (XP) • Extreme programming takes good     software development practices and     pushes them to the li...
Extreme Programming (XP)(Continued) • Extreme programming values are:    • Communication.    • Simplicity.    • Feedback. ...
Alternate Methodologies • Alternate methodologies are available     for analyzing systems. •   These include:     • Protot...
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MELJUN CORTES SAD ch01

  1. 1. Chapter 1Assuming the Role of theSystems Analyst Systems Analysis and DesignMELJUN CORTES
  2. 2. Major Topics • Information systems • Phases of analysis and design • System maintenance • CASE tools • Alternate methodologiesKendall & 2005 PearsonKendall Prentice Hall 1-2
  3. 3. Information • Information is an organizational resource, which must be managed as carefully as other resources. • Costs are associated with information processing. • Information processing must be managed to take full advantage of its potential.Kendall & 2005 PearsonKendall Prentice Hall 1-3
  4. 4. Categories Information systems fall into one of the following eight categories: • Transaction processing systems (TPS). • Office automation systems (OAS). • Knowledge work systems (KWS). • Management information systems (MIS). • Decision support systems (DSS). • Expert systems (ES) and Artificial Intelligence (AI). • Group decision support systems (GDSS) and Computer- Supported Collaborative Work Systems. • Executive support systems (EES).Kendall & 2005 PearsonKendall Prentice Hall 1-4
  5. 5. New Technologies New technologies are being integrated into traditional systems: • Ecommerce uses the Web to perform business activities. • Enterprise Resource Planning (ERP) has the goal of integrating many different information systems within the corporation. • Wireless and handheld devices, including mobile commerce (mcommerce). • Open source software.Kendall & 2005 PearsonKendall Prentice Hall 1-5
  6. 6. Kendall & 2005 PearsonKendall Prentice Hall 1-6
  7. 7. Advantages of Using the Web • The benefits of using the Web are: • Increasing awareness of the availability of the service, product, industry, person, or group. • 24-hour access for users. • Standard interface design. • Creating a global system.Kendall & 2005 PearsonKendall Prentice Hall 1-7
  8. 8. Nature of Analysis and Design Systems analysis and design is a systematic approach to: • Identifying problems, opportunities, and objectives. • Analyzing the information flows in organizations. • Designing computerized information systems to solve a problem.Kendall & 2005 PearsonKendall Prentice Hall 1-8
  9. 9. Systems Analyst • Systems analysts act as: • Outside consultants to businesses. • Supporting experts within a business. • As change agents. • Analysts are problem solvers, and require communication skills. • Analysts must be ethical with users and customers.Kendall & 2005 PearsonKendall Prentice Hall 1-9
  10. 10. Systems Development LifeCycle • The systems development life cycle is a systematic approach to solving business problems. • It is divided into seven phases. • Each phase has unique activities.Kendall & 2005 PearsonKendall Prentice Hall 1-10
  11. 11. Kendall & 2005 PearsonKendall Prentice Hall 1-11
  12. 12. Phase 1 • Identifying: • Problems. • Opportunities. • Objectives. • Personnel involved: • Analyst. • User management. • Systems management.Kendall & 2005 PearsonKendall Prentice Hall 1-12
  13. 13. Phase 2 • Determining information requirements: • Interview management, operations personnel. • Gather systems/operating documents. • Use questionnaires. • Observe the system and personnel involved. • Learn the who, what, where, when, and how, and the why for each of these.Kendall & 2005 PearsonKendall Prentice Hall 1-13
  14. 14. Phase 2 (Continued) • Personnel involved: • Analyst. • User management. • User operations workers. • Systems management.Kendall & 2005 PearsonKendall Prentice Hall 1-14
  15. 15. Phase 3 • Analyzing system needs: • Create data flow diagrams. • Document procedural logic for data flow diagram processes. • Complete the data dictionary. • Make semistructured decisions. • Prepare and present the system proposal. • Recommend the optimal solution to management.Kendall & 2005 PearsonKendall Prentice Hall 1-15
  16. 16. Phase 3 (Continued) • Personnel involved: • Analyst. • User management. • Systems management.Kendall & 2005 PearsonKendall Prentice Hall 1-16
  17. 17. Phase 4 • Designing the recommended system: • Design the user interface. • Design output. • Design input. • Design system controls. • Design files and/or database. • Produce program specifications. • Produce decision trees or tables.Kendall & 2005 PearsonKendall Prentice Hall 1-17
  18. 18. Phase 4 (Continued) • Personnel involved: • Analyst. • System designer. • User management. • User operations workers. • Systems management.Kendall & 2005 PearsonKendall Prentice Hall 1-18
  19. 19. Phase 5 • Developing and documenting software: • Design computer programs using structure charts, Nassi-Schneiderman charts, and pseudocode. • Walkthrough program design. • Write computer programs. • Document software with help files, procedure manuals, and Web sites with Frequently Asked Questions.Kendall & 2005 PearsonKendall Prentice Hall 1-19
  20. 20. Phase 5 (Continued) • Personnel involved: • Analyst. • System designer. • Programmers. • Systems management.Kendall & 2005 PearsonKendall Prentice Hall 1-20
  21. 21. Phase 6 • Testing and maintaining the system: • Test and debug computer programs. • Test the computer system. • Enhance system.Kendall & 2005 PearsonKendall Prentice Hall 1-21
  22. 22. Phase 6 (Continued) • Personnel involved: • Analyst. • System designer. • Programmers. • Systems management.Kendall & 2005 PearsonKendall Prentice Hall 1-22
  23. 23. Phase 7 • Implementing and evaluating the system: • Plan conversion. • Train users. • Purchase and install new equipment. • Convert files. • Install system. • Review and evaluate system.Kendall & 2005 PearsonKendall Prentice Hall 1-23
  24. 24. Phase 7 (Continued) • Personnel involved: • Analyst. • System designer. • Programmers. • User management. • User operations workers. • Systems management.Kendall & 2005 PearsonKendall Prentice Hall 1-24
  25. 25. Rapid ApplicationDevelopment Rapid Application development (RAD) is an object-oriented approach to systems development.Kendall & 2005 PearsonKendall Prentice Hall 1-25
  26. 26. System Maintenance • System maintenance is: • Removing undetected errors, and • Enhancing existing software. • Time spent on maintenance typically ranges from 48-60 percent of total time.Kendall & 2005 PearsonKendall Prentice Hall 1-26
  27. 27. Kendall & 2005 PearsonKendall Prentice Hall 1-27
  28. 28. System Enhancements Systems are enhanced for the following reasons: • Adding additional features to the system. • Business and governmental requirements change over time. • Technology, hardware, and software are rapidly changing.Kendall & 2005 PearsonKendall Prentice Hall 1-28
  29. 29. Kendall & 2005 PearsonKendall Prentice Hall 1-29
  30. 30. CASE Tools • CASE tools are automated, microcomputer-based software packages for systems analysis and design. • Four reasons for using CASE tools are: • To increase analyst productivity. • Facilitate communication among analysts and users. • Providing continuity between life cycle phases. • To assess the impact of maintenance.Kendall & 2005 PearsonKendall Prentice Hall 1-30
  31. 31. CASE Tool Categories CASE tools may be divided into several categories • Upper CASE (also called front-end CASE) tools, used to perform analysis and design. • Lower CASE (also called back-end CASE). These tools generate computer language source code from CASE design. • Integrated CASE, performing both upper and lower CASE functions.Kendall & 2005 PearsonKendall Prentice Hall 1-31
  32. 32. Upper CASE Upper CASE tools: • Create and modify the system design. • Store data in a project repository. • The repository is a collection of records, elements, diagrams, screens, reports, and other project information. • These CASE tools model organizational requirements and define system boundaries.Kendall & 2005 PearsonKendall Prentice Hall 1-32
  33. 33. Lower CASE • Lower CASE tools generate computer source code from the CASE design. • Source code may usually be generated in several languages.Kendall & 2005 PearsonKendall Prentice Hall 1-33
  34. 34. Advantages of GeneratingCode • Time to develop new systems decreases. • The time to maintain generated code is less than to maintain traditional systems. • Computer programs may be generated in more than one language. • CASE design may be purchased from third-party vendors and tailored to organizational needs. • Generated code is free from program coding errors.Kendall & 2005 PearsonKendall Prentice Hall 1-34
  35. 35. Kendall & 2005 PearsonKendall Prentice Hall 1-35
  36. 36. Reverse Engineering • Reverse engineering is generating the CASE design from computer program code. • Source code is examined, analyzed, and converted into repository entities.Kendall & 2005 PearsonKendall Prentice Hall 1-36
  37. 37. Reverse Engineering(Continued) • Reverse engineering produces (depending on the tool set used): • Data structures and elements, describing the files, records, and field. • Screen designs, if the program is online. • Report layouts for batch programs. • A structure chart showing the hierarchy of the modules in the program. • Database design and relationships.Kendall & 2005 PearsonKendall Prentice Hall 1-37
  38. 38. Advantages of ReverseEngineering Reverse Engineering has the following advantages: • Reduced system maintenance time. • Program documentation is produced for loosely documented programs. • Structured programs may be generated from unstructured, older programs. • Future system maintenance is easier to implement. • Unused portions of programs may be eliminated.Kendall & 2005 PearsonKendall Prentice Hall 1-38
  39. 39. Object-Oriented Analysis andDesign • Object-oriented (O-O) analysis and design is used to build object-oriented programs. • O-O programming examines the objects of a system. • Objects are grouped into classes for optimal reuse and maintainability.Kendall & 2005 PearsonKendall Prentice Hall 1-39
  40. 40. The Unified ModelingLanguage • The Unified Modeling Language (UML) is an industry standard for modeling object-oriented systems. • It breaks down a system into a use case model.Kendall & 2005 PearsonKendall Prentice Hall 1-40
  41. 41. Extreme Programming (XP) • Extreme programming takes good software development practices and pushes them to the limit. • It is based on: • Values. • Principles. • Core practices.Kendall & 2005 PearsonKendall Prentice Hall 1-41
  42. 42. Extreme Programming (XP)(Continued) • Extreme programming values are: • Communication. • Simplicity. • Feedback. • Courage.Kendall & 2005 PearsonKendall Prentice Hall 1-42
  43. 43. Alternate Methodologies • Alternate methodologies are available for analyzing systems. • These include: • Prototyping. • ETHICS. • Project Champions. • Soft Systems Methodology. • Multi-view.Kendall & 2005 PearsonKendall Prentice Hall 1-43
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