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Designing new systems or modifying existing ones should always be aimed at helping an organization achieve its goals

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

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Designing new systems or modifying existing ones should always be aimed at helping an organization achieve its goals

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  1. 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 Describe some considerations in design modeling and the diagrams used during object-oriented design Outline key considerations in interface design and control and system security and control. Define the term RFP and discuss how this document is used to drive the acquisition of hardware and software. Describe the techniques used to make systems selection evaluations Principles of Information Systems, Seventh Edition

  2. 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 List the advantages and disadvantages of purchasing versus developing software Discuss the software development process and some of the tools used in this process, including object-oriented program development tools Principles of Information Systems, Seventh Edition

  3. 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

  4. 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

  5. Logical Design • Output requirements • Input requirements • Process requirements • File and database requirements Principles of Information Systems, Seventh Edition

  6. Logical Design (continued) • Telecommunications requirements • Procedure requirements • Controls and security requirements • Personnel and job requirements Principles of Information Systems, Seventh Edition

  7. Physical Design • Hardware specifications • Software specifications • Database specifications Principles of Information Systems, Seventh Edition

  8. Physical Design (continued) • Telecommunications specifications • Personnel specifications • Procedure and control specifications Principles of Information Systems, Seventh Edition

  9. Object-Oriented Design • Design key objects and classes of objects in the new or updated system • Consideration of the problem domain, the operating environment, and the user interface • Consideration of the sequence of events that must happen for the system to function correctly • A sequence of events is often called a scenario • A scenario can be diagrammed in a sequence diagram Principles of Information Systems, Seventh Edition

  10. Figure 13.4: The Levels of the Sign-On Procedure Principles of Information Systems, Seventh Edition

  11. Interface Design and Controls (continued) • Interactive processing • Menu-driven systems • Help commands • Table lookup facilities • Restart procedures Principles of Information Systems, Seventh Edition

  12. Table 13.1: The Elements of Good Interactive Dialogue Principles of Information Systems, Seventh Edition

  13. 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

  14. 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

  15. Generating Systems Design Alternatives • Request for proposal (RFP): a document that specifies in detail required resources such as hardware and software • Financial options Principles of Information Systems, Seventh Edition

  16. Evaluating and Selecting a Systems Design • Preliminary evaluation • To dismiss the unwanted proposals • Begins after all proposals have been submitted • Final evaluation • A detailed investigation of the proposals offered by the vendors remaining after the preliminary evaluation Principles of Information Systems, Seventh Edition

  17. Figure 13.7: The Stages in Preliminary and Final Evaluations Principles of Information Systems, Seventh Edition

  18. Evaluation Techniques • Group consensus • Cost/benefit analysis • Benchmark tests • Point evaluation Principles of Information Systems, Seventh Edition

  19. Figure 13.8: An Illustration of the Point Evaluation System Principles of Information Systems, Seventh Edition

  20. Figure 13.9: Freezing Design Specifications Principles of Information Systems, Seventh Edition

  21. 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

  22. Figure 13.11: Typical Steps in Systems Implementation Principles of Information Systems, Seventh Edition

  23. Acquiring Hardware from an IS Vendor • An IS vendor is a company that offers hardware, software, telecommunications systems, databases, IS personnel, and/or other computer-related resources • Buying computer hardware • Leasing computer hardware • Renting computer hardware • “Pay-as-you-go,” “on-demand,” or “utility” computing Principles of Information Systems, Seventh Edition

  24. Acquiring Software: Make or Buy? • Externally developed software: lower cost, lower risk, ease of installation • In-house developed software • Meeting user and organizational requirements • More features and increased flexibility in terms of customization and changes Principles of Information Systems, Seventh Edition

  25. Acquiring Software: Make or Buy? (continued) • In-house developed software (continued) • Greater potential for providing a competitive advantage • Chief programmer teams • The programming life cycle • Tools and techniques for software development Principles of Information Systems, Seventh Edition

  26. Figure 13.13: Steps in the Programming Life Cycle Principles of Information Systems, Seventh Edition

  27. Tools and Techniques for Software Development • Structured programming • Improving the logical program flow by breaking the program into groups of statements, called structures • CASE tools: used during software development to automate some of the techniques • Object-oriented implementation • A collection of existing modules of code, or objects, can be used across a number of applications Principles of Information Systems, Seventh Edition

  28. Tools and Techniques for Software Development (continued) • Cross-platform development: allows programmers to develop programs that can run on computer systems having different hardware and operating systems, or platforms • Integrated development environment: combines the tools needed for programming with a programming language into one integrated package • Structured walkthrough: a planned and preannounced review of the progress of a program module, a structure chart, or a human procedure Principles of Information Systems, Seventh Edition

  29. Acquiring Database and Telecommunications Systems • Relational databases • Object-oriented database systems • Databases are a blend of hardware and software • Telecommunications systems require a blend of hardware and software Principles of Information Systems, Seventh Edition

  30. User Preparation • Readying managers, decision makers, employees, other users, and stakeholders for new systems • Training users Principles of Information Systems, Seventh Edition

  31. IS Personnel: Hiring and Training • IS manager • Systems analysts • Computer programmers • Data-entry operators Principles of Information Systems, Seventh Edition

  32. Site Preparation • Preparation of the location of a new system • Making room for a computer in an office • Special wiring and air conditioning • Special floor • Additional power circuits Principles of Information Systems, Seventh Edition

  33. Data Preparation • Also called data conversion • Ensuring all files and databases are ready to be used with new computer software and systems Principles of Information Systems, Seventh Edition

  34. Installation • The process of physically placing the computer equipment on the site and making it operational • Normally the manufacturer is responsible for installing computer equipment • Someone from the organization (usually the IS manager) should oversee the process Principles of Information Systems, Seventh Edition

  35. Testing • Unit testing: testing of individual programs • System testing: testing the entire system of programs • Volume testing: testing the application with a large amount of data • Integration testing: testing all related systems together • Acceptance testing: conducting any tests required by the user Principles of Information Systems, Seventh Edition

  36. Start-Up • The process of making the final tested information system fully operational • Direct conversion (also called plunge or direct cutover) • Phase-in approach • Pilot start-up • Parallel start-up Principles of Information Systems, Seventh Edition

  37. User Acceptance • User acceptance document: formal agreement signed by the user that states that a phase of the installation or the complete system is approved Principles of Information Systems, Seventh Edition

  38. 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

  39. Types of Maintenance • Slipstream upgrade • Patch • Release • Version Principles of Information Systems, Seventh Edition

  40. Figure 13.19: Maintenance Costs as a Function of Age Principles of Information Systems, Seventh Edition

  41. Figure 13.20: The Value of Investment in Design Principles of Information Systems, Seventh Edition

  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

  43. Factors to Consider During Systems Review • Mission • Organizational goals • Hardware and software • Database • Telecommunications Principles of Information Systems, Seventh Edition

  44. Factors to Consider During Systems Review (continued) • Information systems personnel • Control • Training • Costs • Complexity Principles of Information Systems, Seventh Edition

  45. Factors to Consider During Systems Review (continued) • Reliability • Efficiency • Response time • Documentation Principles of Information Systems, Seventh Edition

  46. Summary • 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. 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. 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

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