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

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

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

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

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

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

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

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

Business Information 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

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

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

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

Hardware and Software Basics

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

Hardware Components (continued) Figure 2.1: Hardware Components

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

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)

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

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

Output Devices Display monitors (CRTs) Liquid crystal displays (LCDs) 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

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

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

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

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

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

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

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

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

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

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

Data Management

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

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

Figure 3.1: The Hierarchy of Data

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

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

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

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

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

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

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

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?

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

ER diagram for a Customer Order Database

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

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

The Relational Database Model Figure 3.5: A Relational Database Model

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

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

Database Management Systems (DBMS) 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

Overview of Database Types Flat file Simple database program whose records have no relationship to one another Single user Only one person can use the database at a time Examples: Access, FileMaker, and InfoPath Multiple user Allows dozens or hundreds of people to access the same database system at the same time Examples: Oracle, Sybase, and IBM

Distributed Databases Data may be spread across several smaller databases connected via telecommunications devices Corporations get more flexibility in how databases are organized and used Replicated database Holds a duplicate set of frequently used data

Telecommunications

Basic Concepts of Telecommunications Telecommunications: electronic transmission of signals for communications Computer network: communications media, devices, and software needed to connect two or more computer systems or devices Network types: personal area network (PAN), local area network (LAN), metropolitan area network (MAN), wide area network (WAN), and international networks

The Internet Internet: collection of interconnected networks, all freely exchanging information Internet Protocol (IP): communication standard that enables traffic to be routed from one network to another as needed Uniform Resource Locator (URL): an assigned address on the Internet for each computer

Business Networks Intranet: internal corporate network built using Internet and World Wide Web standards and protocols Extranet: network based on Web technologies that links selected resources of a company’s intranet with its customers, suppliers, or other business partners

Systems Development

An Overview of Systems Development Managers and employees in all functional areas work together in a business information system Users help and often lead the way with development process Participants in systems development: Determine when a project fails Are critical to systems development success

Participants in Systems Development Development team consists of the following: Project managers: coordinate system development effort Stakeholders: directly or indirectly benefit from the project Users: interact with the system regularly Systems analysts: analyze and design business systems Programmers: modify or develop programs to satisfy user requirements Various support personnel: specialists, vendors

Information Systems Planning and Aligning Corporate and IS Goals Information systems planning: translating strategic and organizational goals into systems development initiatives Aligning organizational goals and IS goals is critical for any successful systems development effort Determining whether organizational and IS goals are aligned can be difficult

Figure 8.2: Information Systems Planning Information Systems Planning and Aligning Corporate and IS Goals (continued) Figure 8.2: Information Systems Planning

Systems Development Life Cycles The systems development process is also called a systems development life cycle (SDLC) Common SDLCs Prototyping Rapid application development (RAD) Systems development approach that employs tools, techniques, and methodologies designed to speed application development End-user development any systems development project in which the primary effort is undertaken by a combination of business managers and users

Systems Development Activities 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 Systems implementation: creation or acquisition 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 that the system operates as intended and modifies the system so that it continues to meet changing business needs