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Systems Analysis & Design 7 th Edition

Systems Analysis & Design 7 th Edition. Chapter 1. Chapter Objectives . Discuss the impact of information technology on business strategy and success Define an information system and describe its components Explain how profiles and models can represent business functions and operations

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Systems Analysis & Design 7 th Edition

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  1. Systems Analysis & Design7th Edition Chapter 1

  2. Chapter Objectives • Discuss the impact of information technology on business strategy and success • Define an information system and describe its components • Explain how profiles and models can represent business functions and operations • Explain how the Internet has affected business strategies and relationships • Identify various types of information systems and explain who uses them

  3. Chapter Objectives • Explain modeling, prototyping, and CASE tools • Distinguish between structured analysis and object-oriented analysis • Compare the systems development life cycle waterfall model to adaptive models • Discuss the role of the information technology department and the systems analysts who work there

  4. Introduction • Companies use information as a weapon in the battle to increase productivity, deliver quality products and services, maintain customer loyalty, and make sound decisions • Information technology can mean the difference between success and failure

  5. The Impact of Information Technology • Information Technology • Combination of hardware and software products and services that companies use to manage, access, communicate, and share information • A vital asset that must be used effectively, updated constantly, and safeguarded carefully

  6. The Impact of Information Technology • The Future of IT • Accounts for almost 30 percent of America’s economic growth, and the wage gaps between IT workers and all other workers will continue to widen • Global online population skyrocketed between 2000 and 2005

  7. The Impact of Information Technology • The Role of Systems Analysis and Design • Systems Analysis and Design • Step-by-step process for developing high-quality information systems • Systems Analyst • Plan, develop, and maintain information systems

  8. The Impact of Information Technology • Who develops Information Systems? • In-house applications • Software packages • Internet-based application services • Outsourcing • Custom solutions • Enterprise-wide software strategies • How versus What

  9. Information System Components • A system is a set of related components that produces specific results • A mission-critical system is one that is vital to a company’s operations • Data consists of basic facts that are the system’s raw material

  10. Information System Components • Hardware • Moore’s Law • Software • System software • Application software • Enterprise applications • Horizontal system

  11. Information System Components • Software • Vertical system • Legacy systems • Data • Tables • Linking

  12. Information System Components • Processes • Define the tasks and business functions that users, managers, and IT staff members perform to achieve specific results • People • Users, or end users, are the people who interact with an information system, both inside and outside the company

  13. Understanding The Business • Business Process Modeling • Business Profile • Business Models • Business model • Business process • Business process reengineering (BPR)

  14. Understanding The Business • New Kinds of Companies • Production-oriented • Service-oriented • Internet-dependent • Dot-com (.com) • Brick-and-mortar

  15. Impact of the Internet • E-Commerce or I-Commerce • B2C (Business-to-Consumer) • B2B (Business-to-Business) • EDI • Extensible markup language (XML) • Supplier relationship management (SRM)

  16. Impact of the Internet • Web-Based System Development • WebSphere • .NET • Web services

  17. How Business Uses InformationSystems • In past, IT managers divided systems into categories based on the user group the system served • Office systems • Operational systems • Decision support systems • Executive information systems

  18. How Business Uses Information Systems • Today, it makes more sense to identify a system by its functions, rather than by users • Enterprise computing systems • Transaction processing systems • Business support systems • Knowledge management systems • User productivity systems

  19. How Business Uses Information Systems • Enterprise computing systems • Support company-wide operations and data management requirements • Transaction processing systems • Efficient because they process a set of transaction-related commands as a group rather than individually

  20. How Business Uses Information Systems • Business support systems • Provide job-related information to users at all levels of a company • Management information systems (MIS) • Radio frequency identification (RFID) • What-if

  21. How Business Uses Information Systems • Knowledge management systems • Called expert systems • Simulate human reasoning by combining a knowledge base and inference rules • Many use fuzzy logic

  22. How Business Uses Information Systems • User productivity systems • Technology that improves productivity • Groupware • Information systems integration • Most large companies require systems that combine transaction processing, business support, knowledge management, and user productivity features

  23. Information System Users and Their Needs

  24. Information System Users and Their Needs • Top managers • Middle Managers and Knowledge Workers • Supervisors and Team Leaders • Operational Employees

  25. Systems Development Tools and Techniques Tools • Modeling • Models are used to describe and simplify an IS • Prototyping • Test system concepts • Computer-Aided Systems Engineering • CASE tools

  26. Systems Development Tools and Techniques Modeling • Business/Requirements model: Information the systems must provide (Ch 3) • Data model : how data is represented and accessed (ch. 4) • Object model: describe objects which combine data and processes • Network model: the design and protocols of networks • Process model: outlines the logical processes and their interrelationships (Ch 4)

  27. Systems Development Tools and Techniques • Prototyping • Prototype • Speeds up the development process significantly • Important decisions might be made too early, before business or IT issues are thoroughly understood • Can be an extremely valuable tool

  28. Systems Development Tools and Techniques • Computer-Aided Systems Engineering (CASE) Tools • Also called computer-aided software engineering

  29. Systems Development Methods • Alternatives: • Systems development life cycle (SDLC) • Traditional approach • Object-oriented analysis (O-O) • Newer approach • Mixed method

  30. Systems Development Methods • Structured Analysis • Systems development life cycle (SDLC) • Uses a series of phases: Plan, Analyze, Design, Implement, Support • Predictive approach • Process-centered technique • Uses a set of process models to describe a system graphically • Process models – identify data flowing into a process, rules for transformation, and output flows

  31. Systems Development Methods • Sample Process model

  32. Systems Development Methods • Object-oriented Analysis • O-O analysis combines data & processes into objects • Object is a member of a class • Objects possess properties • Methods change an object’s properties • A message requests specific behavior or information from another object

  33. Systems Development Methods • Object-oriented Analysis The PERSON class includes INSTRUCTOR and STUDENT objects, which have their own properties and inherited properties.

  34. Planning and Modeling a Systems Development Project • In addition to selecting a development method, system developers also must create a plan or model for the many tasks that will be required • Typically, the development team will use project management tools to help achieve the end result

  35. Planning and Modeling a Systems Development Project • The SDLC Waterfall Model The phases and deliverables of the SDLC are shown in the waterfall model.

  36. Planning and Modeling a Systems Development Project • The SDLC Waterfall Model • Disadvantage in the built-in structure of the SDLC, because the waterfall model does not emphasize interactivity among the phases • This criticism can be valid if the SDLC phases are followed too rigidly • However, adjacent phases usually interact

  37. Planning and Modeling a Systems Development Project • Adaptive approach – spiral development model builds on a series of iterations.

  38. Planning and Modeling a Systems Development Project • Adaptive Methods and Models • Attempt to develop a system incrementally, by building a series of prototypes and constantly adjusting them to user requirements • Extreme Programming (XP) • Analysts should recognize that these approaches have advantages and disadvantages

  39. Planning and Modeling a Systems Development Project • The SDLC Waterfall Model • Usually includes five steps • Systems planning • Systems analysis • Systems design • Systems implementation • Systems operation, support, and security

  40. Planning and Modeling a Systems Development Project • Systems planning • Systems request • Purpose of this phase is to perform a preliminary investigation whose key part is a feasibility study • Systems Analysis • First step is requirements modeling • End product is the System requirements document

  41. Planning and Modeling a Systems Development Project • Systems Design • Identify all outputs, inputs, and processes • End product is system design specification • Systems Implementation • New system is constructed • Users, managers, IT staff trained to operate and support the system • System evaluation performed

  42. Planning and Modeling a Systems Development Project • Systems Operation, Support, and Security • A well-designed system must be secure, reliable, maintainable, and scalable • After several years of operation, systems need extensive changes • SDLC ends with system replacement

  43. Planning and Modeling a Systems Development Project • Joint Application Development and Rapid Application Development Methods and Models • Joint application development (JAD) • Rapid application development (RAD) • Other Development Methods and Models • Rational Unified Process (RUP®) • Microsoft Solutions Framework (MSF)

  44. Planning and Modeling a Systems Development Project • The Importance of Project Management • Regardless of the development strategy, people, tasks, timetables, and expenses must be managed effectively • Complex projects can involve dozens of people, hundreds of tasks, and many thousands of dollars

  45. Systems Development Guidelines • Stick to a plan • Involve the users throughout the development process • Listening is very important • Use project management tools to identify tasks and milestones • Remain flexible • Develop accurate cost and benefit information

  46. Information Technology Department • The information technology (IT) department develops and maintains a company’s information systems • The IT group provides technical support

  47. Information Technology Department • Application Development • Team may include users, managers and IT Staff members • Systems Support and Security • Deployment team • User Support • Help desk or information center (IC)

  48. Information Technology Department • Database Administration • Database design, management, security, backup, and user access • Network Administration • Includes hardware and software maintenance, support, and security • Web Support • Webmasters

  49. Information Technology Department • Quality Assurance (QA) • Reviews and tests all applications and systems changes to verify specifications and software quality standards • Is a separate unit that reports directly to IT management

  50. The Systems Analyst Position • A systems analyst investigates, analyzes, designs, develops, installs, evaluates, and maintains a company’s information systems • On large projects, the analyst works as a member of an IT department team • Smaller companies often use consultants to perform the work

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