Ch12-13 Systems Development

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Ch12-13 Systems Development

  1. 1. Systems Development
  2. 2. • Effective systems development requires a team effort from stakeholders, users, managers, systems development specialists, and various support personnel, and it starts with careful planning • Identify the key participants in the systems development process and discuss their roles • Identify important system performance requirements of transaction processing applications that run on the Internet or a corporate intranet or extranet Principles of Information Systems, Seventh Edition 2
  3. 3. • Systems development often uses tools to select, implement, and monitor projects • Discuss the key features, advantages, and disadvantages of the traditional, prototyping, rapid application development, and end-user systems development life cycles • Identify several factors that influence the success or failure of a systems development project Principles of Information Systems, Seventh Edition 3
  4. 4. • Systems development starts with investigation and analysis of existing systems • State the purpose of systems investigation • Discuss the importance of performance • State the purpose of systems analysis and discuss some of the tools and techniques used in this phase of systems development Principles of Information Systems, Seventh Edition 4
  5. 5. • Designing new systems or modifying existing ones should always be aimed at helping an organization achieve its goals • State the purpose of systems design and discuss the differences between logical and physical systems design Principles of Information Systems, Seventh Edition 5
  6. 6. • The primary emphasis of systems implementation is to make sure that the right information is delivered to the right person in the right format at the right time • State the purpose of systems implementation and discuss the various activities associated with this phase of systems development Principles of Information Systems, Seventh Edition 6
  7. 7. • Maintenance and review add to the useful life of a system but can consume large amounts of resources. These activities can benefit from the same rigorous methods and project management techniques applied to systems development. • State the importance of systems and software maintenance and discuss the activities involved • Describe the systems review process Principles of Information Systems, Seventh Edition 7
  8. 8. An Overview of Systems Development: Participants in Systems Development • Development team • Responsible for determining the objectives of the information system and delivering a system that meets these objectives • Usually consists of stakeholders, users, managers, systems development specialists, and various support personnel Principles of Information Systems, Seventh Edition 8
  9. 9. Figure 12.1: Systems analyst plays an important role in the development team Principles of Information Systems, Seventh Edition 9
  10. 10. Initiating Systems Development • Systems development begins when an individual or group capable of initiating organizational change perceives a need for a new or modified system • Systems development initiatives arise from all levels of an organization • Systems development initiatives are both planned and unplanned • Systems development projects may be initiated for a number of reasons Principles of Information Systems, Seventh Edition 10
  11. 11. Figure 12.2: Typical Reasons to Initiate a Systems Development Project Principles of Information Systems, Seventh Edition 11
  12. 12. Establishing Objectives for Systems Development: Performance Objectives • Output quality or usefulness • Output accuracy • Output format quality or usefulness • Speed at which output is produced • Scalability of the resulting system Principles of Information Systems, Seventh Edition 12
  13. 13. Cost Objectives • Development costs • Uniqueness costs • Fixed investments • Ongoing operating costs Principles of Information Systems, Seventh Edition 13
  14. 14. Web-Based Systems Development: The Internet, Intranets, Extranets, and E-Commerce • Internet technology enables companies to extend their information systems beyond their boundaries to reach their customers, suppliers, and partners • Dynamic core business application that runs over the Web • Must be reliable and fault tolerant • Must integrate with existing infrastructure • Development and maintenance must be quick and easy Principles of Information Systems, Seventh Edition 14
  15. 15. Systems Development Life Cycles • The systems development process is also called a systems development life cycle (SDLC) • The later in the SDLC an error is detected, the more expensive it is to correct Principles of Information Systems, Seventh Edition 15
  16. 16. Systems Development Life Cycles (continued) • Common systems development life cycles: • Traditional • Prototyping • Rapid application development (RAD) • End-user development Principles of Information Systems, Seventh Edition 16
  17. 17. Figure 12.6: The Traditional Systems Development Life Cycle Principles of Information Systems, Seventh Edition 17
  18. 18. The Traditional Systems Development Life Cycle • Systems investigation: problems and opportunities are identified and considered in light of the goals of the business • Systems analysis: study of existing systems and work processes to identify strengths, weaknesses, and opportunities for improvement • Systems design: defines how the information system will do what it must do to obtain the problem solution Principles of Information Systems, Seventh Edition 18
  19. 19. The Traditional Systems Development Life Cycle (continued) • Systems implementation: the creation or acquiring of various system components detailed in the systems design, assembling them, and placing the new or modified system into operation • Systems maintenance and review: ensures the system operates and modifies the system so that it continues to meet changing business needs Principles of Information Systems, Seventh Edition 19
  20. 20. Prototyping • An iterative approach to the systems development process • Operational prototype: a functioning prototype that accesses real data files, edits input data, makes necessary computations and comparisons, and produces real output • Nonoperational prototype: a mock-up, or model, that includes output and input specifications and formats Principles of Information Systems, Seventh Edition 20
  21. 21. Rapid Application Development, Agile Development, Joint Application Development, and Other Systems Development Approaches • Rapid application development (RAD): a systems development approach that employs tools, techniques, and methodologies designed to speed application development • RAD makes extensive use of the joint application development (JAD) process for data collection and requirements analysis Principles of Information Systems, Seventh Edition 21
  22. 22. The End-User Systems Development Life Cycle • Any systems development project in which the primary effort is undertaken by a combination of business managers and users • End-user-developed systems can be structured as complementary to, rather than in conflict with, existing and emerging information systems Principles of Information Systems, Seventh Edition 22
  23. 23. Table 12.5: When to Use Outsourcing for Systems Development Principles of Information Systems, Seventh Edition 23
  24. 24. Table 12.5: When to Use Outsourcing for Systems Development (continued) Principles of Information Systems, Seventh Edition 24
  25. 25. Factors Affecting Systems Development Success • Degree of change • Continuous improvement versus reengineering • Managing change • Quality and standards • Use of project management tools • Use of Computer-Aided Software Engineering (CASE) tools • Automate many of the tasks required in a systems development effort and enforce adherence to the SDLC Principles of Information Systems, Seventh Edition 25
  26. 26. Systems Investigation • What primary problems might a new or enhanced system solve? • What opportunities might a new or enhanced system provide? • What new hardware, software, databases, telecommunications, personnel, or procedures will improve an existing system or are required in a new system? • What are the potential costs (variable and fixed)? • What are the associated risks? Principles of Information Systems, Seventh Edition 26
  27. 27. Figure 12.12: The Systems Investigation Team Principles of Information Systems, Seventh Edition 27
  28. 28. Figure 12.13: Technical, Economic, Legal, Operational, and Schedule Feasibility Principles of Information Systems, Seventh Edition 28
  29. 29. The Systems Investigation Report • Summarizes the results of systems investigation and the process of feasibility analysis • Recommends a course of action: continue on into systems analysis, modify the project in some manner, or drop it Principles of Information Systems, Seventh Edition 29
  30. 30. Systems Analysis • Steps of a formalized analysis procedure: • Assembling the participants for systems analysis • Collecting appropriate data and requirements • Analyzing the data and requirements • Preparing a report on the existing system, new system requirements, and project priorities Principles of Information Systems, Seventh Edition 30
  31. 31. The Systems Analysis Report • The systems analysis report should cover: • The strengths and weaknesses of the existing system from a stakeholder’s perspective • The user/stakeholder requirements for the new system (also called the functional requirements) • The organizational requirements for the new system • A description of what the new information system should do to solve the problem Principles of Information Systems, Seventh Edition 31
  32. 32. Systems Design • Answers the question “How will the information system do what it must do to solve a problem?” • Has two dimensions: logical and physical • Logical design: description of the functional requirements of a system • Physical design: specification of the characteristics of the system components necessary to put the logical design into action Principles of Information Systems, Seventh Edition 32
  33. 33. Logical Design • Output requirements • Input requirements • Process requirements • File and database requirements Principles of Information Systems, Seventh Edition 33
  34. 34. Logical Design (continued) • Telecommunications requirements • Procedure requirements • Controls and security requirements • Personnel and job requirements Principles of Information Systems, Seventh Edition 34
  35. 35. Physical Design • Hardware specifications • Software specifications • Database specifications Principles of Information Systems, Seventh Edition 35
  36. 36. Physical Design (continued) • Telecommunications specifications • Personnel specifications • Procedure and control specifications Principles of Information Systems, Seventh Edition 36
  37. 37. Design of System Security and Controls • Preventing, detecting, and correcting errors • Disaster planning and recovery • Disaster planning: the process of anticipating and providing for disasters • Disaster recovery: the implementation of the disaster plan • Hardware backup Principles of Information Systems, Seventh Edition 37
  38. 38. Design of System Security and Controls (continued) • Disaster planning and recovery (continued) • Software and database backup • Telecommunications backup • Personnel backup • Systems controls: rules and procedures to maintain data security Principles of Information Systems, Seventh Edition 38
  39. 39. The Design Report • Primary result of systems design • Reflects the decisions made and prepares the way for systems implementation Principles of Information Systems, Seventh Edition 39
  40. 40. Figure 13.11: Typical Steps in Systems Implementation Principles of Information Systems, Seventh Edition 40
  41. 41. Systems Operation and Maintenance • Systems operation: use of a new or modified system • Systems maintenance: checking, changing, and enhancing the system to make it more useful in achieving user and organizational goals Principles of Information Systems, Seventh Edition 41
  42. 42. Systems Review • Process of analyzing systems to make sure that they are operating as intended • Often compares the performance and benefits of the system as it was designed with the actual performance and benefits of the system in operation • Event-driven review: review triggered by a problem or opportunity such as an error, a corporate merger, or a new market for products • Time-driven review: review performed after a specified amount of time Principles of Information Systems, Seventh Edition 42
  43. 43. Factors to Consider During Systems Review • • • • • • Mission Organizational goals Hardware and software Database Telecommunications Information systems personnel • Control Principles of Information Systems, Seventh Edition • • • • • • • Training Costs Complexity Reliability Efficiency Response time Documentation 43
  44. 44. Summary • Systems development begins when an individual or group capable of initiating organizational change perceives a need for a new or modified system • Information systems planning is the translation of strategic and organizational goals into systems development initiatives • Aligning organizational goals and IS goals is critical for any successful systems development effort • Common systems development life cycles are traditional, prototyping, rapid application development (RAD), and end-user development Principles of Information Systems, Seventh Edition 44
  45. 45. Summary (continued) • Phases of the traditional systems development life cycle: systems investigation, systems analysis, systems design, systems implementation, and systems maintenance and review • During systems investigation, problems and opportunities are identified and considered in light of the goals of the business • Systems analysis involves the study of existing systems and work processes to identify strengths, weaknesses, and opportunities for improvement Principles of Information Systems, Seventh Edition 45
  46. 46. Summary (continued) • Computer-Aided Software Engineering (CASE) tools automate many of the tasks required in a systems development effort and enforce adherence to the SDLC • Object-oriented systems development is an approach to systems development that combines the logic of the systems development life cycle with the power of objectoriented modeling and programming Principles of Information Systems, Seventh Edition 46
  47. 47. Summary (continued) • Systems design answers the question “How will the information system do what it must do to solve a problem?” • Systems design has two dimensions: logical and physical • Logical design is description of the functional requirements of a system • Physical design is specification of the characteristics of the system components necessary to put the logical design into action Principles of Information Systems, Seventh Edition 47
  48. 48. Summary (continued) • Steps of systems implementation: hardware acquisition, software acquisition, user preparation, personnel: hiring and training, site preparation, data preparation, installation, testing, start-up, and user acceptance • Systems operation is the use of a new or modified system • Systems maintenance involves checking, changing, and enhancing the system to make it more useful in achieving user and organizational goals Principles of Information Systems, Seventh Edition 48
  49. 49. Summary (continued) • Systems review is the process of analyzing systems to make sure that they are operating as intended • Event-driven review is triggered by a problem or opportunity such as an error, a corporate merger, or a new market for products • Time-driven review is performed after a specified amount of time Principles of Information Systems, Seventh Edition 49

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