Material fromFundamentals of Information Systems,

Fourth EditionBy

Ralph Stair and George Reynolds

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Basics of Information Systems

Information Concepts: Data, Information, and

Knowledge

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• 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

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Figure 1.2: The Process of Transforming Data into Information

Data, Information, and Knowledge

The Characteristics of Valuable Information

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Table 1.2: Characteristics of Valuable Information

The Characteristics of Valuable Information (continued)

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Table 1.2: Characteristics of Valuable Information (continued)

What Is an Information System?

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Figure 1.3: The Components of any Information System

Computer-Based Information Systems

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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

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• 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

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Most common types of information systems used in business organizationsElectronic and mobile commerce systemsTransaction processing systemsManagement information systemsDecision support systemsSpecialized business information systems

Electronic and Mobile Commerce

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E-commerce: any business transaction executed electronically between partiesCompanies (B2B)Companies and consumers (B2C)Consumers and other consumers (C2C)Companies and the public sectorConsumers and the public sector

Transaction Processing Systems

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Transaction: business-related exchangePayments to employeesSales to customersPayments 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

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• 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

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Hardware Components

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• 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)

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Figure 2.1: Hardware Components

Processing and Memory Devices: Power and Speed

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• 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

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• 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

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• 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

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• 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

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• 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

Overview of Software

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• 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

Application Software

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• 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

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Serves the needs of an individual userIncludes personal productivity software

Enables users to improve their personal effectiveness

Personal Application Software (continued)

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Table 2.7: Examples of Personal Productivity Software

Personal Application Software (continued)

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Table 2.7: Examples of Personal Productivity Software (continued)

Workgroup Application Software

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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

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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)

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Table 2.10: Examples of Enterprise Application Software

Information, Decision Support,and Specialized Software

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Used in businesses of all sizes and types to increase profits or reduce costs

Available in every industryExample: analysis to increase the cure rate for

cancer

Data Management

Data Management

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Without data and the ability to process it, an organization could not successfully complete most business activities

Data consists of raw factsFor data to be transformed into useful

information, it must first be organized in a meaningful way

The Hierarchy of Data

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• 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

The Hierarchy of Data

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Figure 3.1: The Hierarchy of Data

Data Entities, Attributes, and Keys

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• 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

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Figure 3.2: Keys and Attributes

The Database Approach

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• 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

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Figure 3.3: The Database Approach to Data Management

The Database Approach Advantages

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Table 3.1: Advantages of the Database Approach

The Database Approach (continued)

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Table 3.1: Advantages of the Database Approach (continued)

The Database Approach Disadvantages

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Table 3.2: Disadvantages of the Database Approach

Data Modeling and the Relational Database Model

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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

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• 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

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ER diagram Showing the Relationship between the Manager, Department and

Project

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Implementing the Relational Database Model

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data elements are placed in two-dimensional tables (relations), which are the logical equivalent of files

Each row of a table represents a data entityColumns of the table represent attributesThe domain of the database model consists

of all of the allowable values for data attributes i

The Relational Database Model

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Figure 3.5: A Relational Database Model

Manipulating Databases

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Selecting: eliminates rows according to criteria

Projecting: eliminates columns in a tableJoining: combines two or more tablesLinking: relates or links two or more tables

using common data attributes

Manipulating Data (continued)

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Figure 3.7: Linking Data Tables to Answer an Inquiry

Database Management Systems (DBMS)

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• 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

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• 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

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Distributed databaseData may be spread across several smaller

databases connected via telecommunications devices

Corporations get more flexibility in how databases are organized and used

Replicated databaseHolds a duplicate set of frequently used data

Telecommunications

Basic Concepts of Telecommunications

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• 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

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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

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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

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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 failsAre critical to systems development success

Participants in Systems Development

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• 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

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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

Information Systems Planning and Aligning Corporate and IS Goals (continued)

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Figure 8.2: Information Systems Planning

Systems Development Life Cycles

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• 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

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• 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