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Basics of Information Systems

Basics of Information Systems

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Basics of Information Systems

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  1. Basics of Information Systems Material from Fundamentals of Information Systems, Fourth Edition By Ralph Stair and George Reynolds

  2. Information Concepts:Data, Information, and Knowledge • Data: raw facts • Alphanumeric, image, audio, and video • Information: collection of facts organized in such a way that they have additional value beyond the value of the facts themselves • Value of Information is directly linked to how it helps decision makers achieve their organization’s goals and can be measured • in time required to make a decision • Increased profits to the company

  3. Data, Information, and Knowledge Figure 1.2: The Process of Transforming Data into Information

  4. The Characteristics of Valuable Information Table 1.2: Characteristics of Valuable Information

  5. The Characteristics of Valuable Information (continued) Table 1.2: Characteristics of Valuable Information (continued)

  6. What Is an Information System? Figure 1.3: The Components of any Information System

  7. Computer-Based Information Systems • Computer-based information system (CBIS): single set of hardware, software, databases, telecommunications, people, and procedures configured to collect, manipulate, store, and process data into information

  8. Computer-Based Information Systems • CBIS components • Hardware: computer equipment used to perform input, processing, and output activities • Software: computer programs that govern the operation of the computer • Database: organized collection of facts and information • Telecommunications: electronic transmission of signals for communications • Networks: connect computers and equipment in a building, around the country, and around the world

  9. BusinessInformation Systems • Most common types of information systems used in business organizations • Electronic and mobile commerce systems • Transaction processing systems • Management information systems • Decision support systems • Specialized business information systems

  10. Electronic and Mobile Commerce • E-commerce: any business transaction executed electronically between parties • Companies (B2B) • Companies and consumers (B2C) • Consumers and other consumers (C2C) • Companies and the public sector • Consumers and the public sector

  11. Transaction Processing Systems • Transaction: business-related exchange • Payments to employees • Sales to customers • Payments to suppliers • Transaction processing system (TPS): organized collection of people, procedures, software, databases, and devices used to record completed business transactions

  12. Additional Business Information Systems • Management Information Systems (MIS) • provide routine information to managers and decision makers • Knowledge Management Systems (KMS) • create, store, share, and use the organization’s knowledge and experience • Artificial intelligence (AI) • field in which the computer system takes on the characteristics of human intelligence • Decision support system (DSS) • used to support problem-specific decision making

  13. Hardware and Software Basics

  14. Hardware Components • Central processing unit (CPU) • Arithmetic/logic unit (ALU): performs calculations and makes logical comparisons • Control unit: accesses, decodes and coordinates data in CPU and other devices • Primary memory: holds program instructions and data for processing • Secondary storage: more permanent storage • Input and output devices • Communications devices

  15. Hardware Components (continued) Figure 2.1: Hardware Components

  16. Processing and Memory Devices: Power and Speed • System unit • Houses the components responsible for processing (the CPU and memory) • All other computer system devices are linked either directly or indirectly into the system unit housing • Clock speed • series of electronic pulses produced at a predetermined rate that affects machine cycle time • Clock speed is often measured in megahertz (MHz) for millions or gigahertz(GHz) for billions of cycles per second

  17. Memory and Storage Characteristics and Functions • Types of Memory • Random access memory (RAM) • Temporary • Volatile • Read-only memory (ROM) • Usually nonvolatile • Secondary storage • Also called permanent storage • Nonvolatile • Greater capacity and greater economy than memory • Measured in bytes: kilo, mega, giga, tera • Different access methods • Sequential access: data must be accessed in the order in which it is stored • Sequential access storage devices (SASDs) • Direct access: data can be retrieved in any order • Direct access storage devices (DASDs)

  18. Secondary Storage Devices • Magnetic tapes • Secondary storage used primarily for backups • Magnetic disks • Direct access secondary storage, e.g., hard disk • RAID • Stores extra bits so that data can be reconstructed if system fails • SAN • Provides high-speed connections between data storage devices and computers over a network Optical disks • Direct access optical disc, e.g., CD-ROM • Digital video disk (DVD) • Stores several gigabytes of data • Flash memory • Nonvolatile silicon computer chip

  19. Input Devices • Personal computer input devices • Keyboard, mouse • Speech-recognition technology • Input devices that recognize human speech • Digital cameras • Input device used with PC to record/store images in digital form • Terminals • Input and display devices that perform data entry and input at the same time • Touch-sensitive screens • Allow display screens to act as input devices as well as output devices • Bar-code scanners • Employs a laser scanner to read a bar-coded label • Magnetic ink character recognition (MICR) devices • Code data on banking forms, such as checks Pen input devices • Activate a command, enter handwritten notes, and draw objects • Radio Frequency Identification (RFID) • Employs a microchip with an antenna to broadcast its unique identifier and location to a receiver

  20. Output Devices • Display monitors (CRTs) • Output quality measured by number of pixels and dot pitch • Liquid crystal displays (LCDs) • Easier on eyes, use less electricity, take up less space than CRTs • Organic light-emitting diodes (OLEDs) • Directly emits light rather than using backlight • Sharper colors and thinner displays Printers and plotters: hard copy output • Printers: laser, inkjet • Plotters: used for general design work • Digital audio player • Stores, organizes, and plays digital music files

  21. Overview of Software • Computer programs: sequences of instructions for the computer • Documentation:describes program functions • Systems software:coordinates the activities of hardware and programs • Application software: helps users solve particular problems

  22. Systems Software • Controlling operations of computer hardware • Supports application programs’ problem-solving capabilities • Different types of systems software include: • Operating systems programs that control the hardware and interface with applications • Common hardware functions • Get input (e.g., keyboard) • Retrieve data from disks and store data on disks • Display information on a monitor or printer • User interface • Allows individuals to access and command the computer system • Command-based user interface: uses text commands • Graphical user interface (GUI): uses icons and menus to send commands to the computer system • Utility programs

  23. Application Software • Give users the ability to solve problems and perform specific tasks • Interact with systems software; systems software then directs the hardware to perform tasks • Proprietary software: unique program for a specific application, usually developed and owned by a single company • Off-the-shelf software: existing software program that can be purchased • Customized package

  24. Personal Application Software • Serves the needs of an individual user • Includes personal productivity software • Enables users to improve their personal effectiveness

  25. Personal Application Software (continued) Table 2.7: Examples of Personal Productivity Software

  26. Personal Application Software (continued) Table 2.7: Examples of Personal Productivity Software (continued)

  27. Workgroup Application Software • Workgroup application software: support teamwork, whether people are in the same location or dispersed around the world • Groupware: software that helps groups of people work together more efficiently and effectively

  28. Enterprise Application Software • Software that benefits an entire organization • Enterprise resource planning (ERP) software: programs that manage a company’s vital business operations for an entire multisite, global organization

  29. Enterprise Application Software (continued) Table 2.10: Examples of Enterprise Application Software

  30. Information, Decision Support,and Specialized Software • Used in businesses of all sizes and types to increase profits or reduce costs • Available in every industry • Example: analysis to increase the cure rate for cancer

  31. Data Management

  32. Data Management • Without data and the ability to process it, an organization could not successfully complete most business activities • Data consists of raw facts • For data to be transformed into useful information, it must first be organized in a meaningful way

  33. The Hierarchy of Data • Bit (a binary digit): a circuit that is either on or off • Byte: eight bits • Character: basic building block of information • Each byte represents a character • Can be an uppercase letter, lowercase letter, numeric digit, or special symbol • Field: typically a name, number, or combination of characters that describes an aspect of a business object or activityRecord: a collection of related data fields • File: a collection of related records • Database: a collection of integrated and related files • Hierarchy of data: bits, characters, fields, records, files, and databases

  34. The Hierarchy of Data Figure 3.1: The Hierarchy of Data

  35. Data Entities, Attributes, and Keys • Entity: a generalized class of people, places, or things (objects) for which data is collected, stored, and maintained • Attribute: characteristic of an entity • Data item: value of an attribute • Key: field or set of fields in a record that is used to identify the record • Primary key: field or set of fields that uniquely identifies the record

  36. Data Entities, Attributes, and Keys Figure 3.2: Keys and Attributes

  37. The Database Approach • Traditional approach to database management • separate data files are created for each application • Results in data redundancy (duplication) • Data redundancy conflicts with data integrity • Database approach to database management: • pool of related data is shared by multiple applications • Significant advantages over traditional approach

  38. The Database Approach to Data Management Figure 3.3: The Database Approach to Data Management

  39. The Database Approach Advantages Table 3.1: Advantages of the Database Approach

  40. The Database Approach (continued) Table 3.1: Advantages of the Database Approach (continued)

  41. The Database Approach Disadvantages Table 3.2: Disadvantages of the Database Approach

  42. Data Modeling and the Relational Database Model • When building a database, consider: • Content: What data should be collected, at what cost? • Access: What data should be provided to which users and when? • Logical structure: How should data be arranged to make sense to a given user? • Physical organization: Where should data be physically located?

  43. Data Modeling • Building a database requires two types of designs • Logical design • Abstract model of how data should be structured and arranged to meet an organization’s information needs • Data model: a diagram of data entities and their relationships • Entity-relationship (ER) diagrams: data models that use basic graphical symbols to show the organization of and relationships between data • Physical design • Fine-tunes the logical database design for performance and cost considerations

  44. ER diagram for a Customer Order Database

  45. ER diagram Showing the Relationship between the Manager, Department and Project

  46. Implementing the Relational Database Model • data elements are placed in two-dimensional tables (relations), which are the logical equivalent of files • Each row of a table represents a data entity • Columns of the table represent attributes • The domain of the database model consists of all of the allowable values for data attributes i

  47. The Relational Database Model Figure 3.5: A Relational Database Model

  48. Manipulating Databases • Selecting: eliminates rows according to criteria • Projecting: eliminates columns in a table • Joining: combines two or more tables • Linking: relates or links two or more tables using common data attributes

  49. Manipulating Data (continued) Figure 3.7: Linking Data Tables to Answer an Inquiry

  50. Interface between: Database and application programs Database and the user Creating and implementing the right database system ensures that the database will support both business activities and goals DBMS: a group of programs used as an interface between a database and application programs or a database and the user Database Management Systems (DBMS)