Basics of Information Systems

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Nov 6, 2013 (3 years and 11 months ago)

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Material from

Fundamentals of Information Systems, Fourth Edition

By

Ralph Stair and George Reynolds



1

Basics of Information Systems

Information Concepts
:


Data, Information, and Knowledge

2


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

Figure 1.2: The Process of Transforming Data into Information

Data, Information, and Knowledge

The Characteristics of Valuable
Information

4

Table 1.2: Characteristics of Valuable Information

The Characteristics of Valuable
Information (continued)

5

Table 1.2: Characteristics of Valuable Information (continued)

What Is an Information System?


6

Figure 1.3: The Components of any Information System

Computer
-
Based Information Systems

7


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

8


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

9


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

10


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

11


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

12


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

1
3

Hardware Components

14


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)

15

Figure 2.1: Hardware Components

Processing and Memory Devices:
Power and Speed

16


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

17


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

18


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

19


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


20


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


21


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

23


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

24


Serves the needs of an individual user


Includes personal productivity software


Enables users to improve their personal effectiveness



Personal Application Software
(continued)

25

Table 2.7: Examples of Personal Productivity Software

Personal Application Software
(continued)

26

Table 2.7: Examples of Personal Productivity Software (continued)

Workgroup Application Software

27


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

28


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)

29

Table 2.10: Examples of Enterprise Application Software

Information
, Decision Support,

and Specialized
Software

30


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

32


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

33


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
activity
Record
:

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

34

Figure 3.1: The Hierarchy of Data

Data Entities, Attributes, and Keys

35


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

36

Figure 3.2: Keys and Attributes


The Database Approach

37


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

38

Figure 3.3: The Database Approach to Data Management

The Database Approach Advantages

39

Table 3.1: Advantages of the Database Approach

The Database Approach (continued)

40

Table 3.1: Advantages of the Database Approach (continued)

The Database Approach
Disadvantages

41

Table 3.2: Disadvantages of the Database Approach

Data Modeling and the Relational
Database Model

42


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

43


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

44


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

45

Implementing the
Relational Database
Model

46


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

47

Figure 3.5: A Relational Database Model

Manipulating Databases

48


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)

49

Figure 3.7: Linking Data Tables to Answer an Inquiry

Database Management Systems
(DBMS)

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


Overview of Database Types

51


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

52


Distributed database


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

54


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

55


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

56


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

58


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

59


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

60


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)

61

Figure 8.2: Information Systems Planning

Systems Development Life Cycles

62


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

63


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