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Transcript of Chapter 4 Uma Gupta Introduction to Information Systems 2000 by Prentice Hall. 4-1 Computer...
2000 by Prentice Hall. 4-1
Chapter 4
Uma GuptaIntroduction to Information Systems
Computer Software
2000 by Prentice Hall. 4-2
Learning Objectives
After studying this chapter, you will be able to:
Describe different types of system software, including operating systems
Discuss important types of application software Explain the concept of programming and identify
different programming languages
2000 by Prentice Hall. 4-3
The Two Main Types of Software
• Performs basic functions tostart a computer
• Controls, coordinates, and manages all computer-relatedresources
System Software
• Automates and performsdifferent functions like payroll,inventory, and sales analysis
Application Software
Software
2000 by Prentice Hall. 4-4
The Three Major Categories of System Software
Software Type Description
Programs that manage the resources in a computer, such as memory and printers
Programs that implement different programs, such as payroll and credit card processing
Programs that help developers create information systems
System control software
System support software
System development software
2000 by Prentice Hall. 4-5
The Three Main Functions of an Operating System
• Manage computer resources
• Ensure efficient memory use
• Optimize CPU performance
• Keep track of systemresources
Resource Management
• Load programs andfiles into memory
• Read, create, and dorelated tasks with files
File Management
OPERATINGSYSTEM FUNCTIONS
• Help users interfacewith computers
• Select and manage input/output devicesand applicationprograms
• Resolve and track errors, conflicts, andsecurity features
• Manage multitasking
User Management
2000 by Prentice Hall. 4-6
Operating System Environments
Environment Description
Multiple programs can be run on a computer at the same time. The CPU switches between programs. However, at any given time it is executing one program.
A multiprocessing system has a number of CPUs that process data and instructions, unlike systems that have only one CPU. Ideally suited for complex and computationally intensive operations that require extensive processing.
Multiprogramming
Multiprocessing
2000 by Prentice Hall. 4-7
Types of Operating Systems
MS-DOS DOS (disk operating system), was once a
popular operating system for PCs DOS is cryptic and not user-friendly
Windows Operating System The most widely used operating systems for
personal computers, is driven by graphical user interfaces (GUI)
Introduced multitasking capabilities
2000 by Prentice Hall. 4-8
Types of Operating Systems (cont.)
Windows NT An advanced 32-bit operating system that is totally
independent of the DOS operating system Ideally suited for large business applications that run
in a networked environment
UNIX Operating System Allows multiple users doing multiple tasks to work on
the computer at the same time Comes in both a 32-bit and 64-bit versions A lack of standardization is one disadvantage of UNIX
2000 by Prentice Hall. 4-9
Types of Operating Systems (cont.)
The OS/2 Operating System A 32-bit, single-user operating system from
IBM that supports multitasking Provides both a graphical user interface and a
means for users to enter verbal commands
Linux Is becoming a stable operating system with
many of the same features and functions as Windows NT
2000 by Prentice Hall. 4-10
Types of Operating Systems (cont.)
Mac OS Unlike PCs that rely on Intel chips, Apple’s
Power Macs and iMac rely on the PowerPC CPU chip
Mac OS, the operating system for Macintoshes, is a multitasking operating system with numerous features and graphical capabilities that make Macintoshes popular in publishing, marketing, and educational organizations
2000 by Prentice Hall. 4-11
Application Software
Software designed to perform people-related tasks such as payroll, inventory, and sales analysis.
2000 by Prentice Hall. 4-12
Five Types of General-Purpose Application Software
Type of ApplicationSoftware Description
Allows easy creation, management, correction, and manipulation of text documents.
Produces documents such as memos and pamphlets. Has many word-processing features but has more sophisticated text and graphics capabilities.
Uses electronic calculators for extensive number crunching, such as financial analysis, budget preparation, other numerical analysis, and “what-if” analysis.
Provides for the creation and management of sophisticated graphics, charts, and figures. Often comes with extensive color capabilities and clip art.
Scans text and graphics from paper documents and converts them into digital images.
Word processing
Computer graphics
Desktop publishing
Spreadsheets
Imaging
2000 by Prentice Hall. 4-13
General-Purpose Software
Software mass produced for a broad range of common business applications such as word processing, graphics, payroll, and accounting.
2000 by Prentice Hall. 4-14
Application-Dedicated Software
Specialized or customized software designed to meet specific information needs of users.
2000 by Prentice Hall. 4-15
Different Generations of Software Programming Languages
Generation ofLanguage Description
The only language that the computer understands. It is represented in Os and 1s.
A symbolic language that uses abbreviations and symbols. An improvement over machine language.
An improvement over assembly language. It is closer to the human language than earlier languages. They are machine-independent.
Programming languages that require users to specify only what needs to be done, not how it has to be done.
First Machine language
Fourth INTELLECT FOCUS
Second Assembler language
Third BASIC COBOL FORTRAN PASCAL
2000 by Prentice Hall. 4-16
Object-Oriented Programming
A programming language that treats different real-world entities (places, persons, things, or ideas) as objects. Each object comes with its own data and code that specifies how the object should behave.
2000 by Prentice Hall. 4-17
Visual Programming
Programming languages that allow users to visualize their code and its impact on the system.
2000 by Prentice Hall. 4-18
Business Guidelines for Software Success
Software for Personal Success Individuals should carefully assess the expected
returns from software
Plan for Quality Programmers are not encouraged to plan their
program or produce quality products because they are evaluated on the number of lines of code produced
However, quality usually requires teamwork; teams of software experts develop almost all software of any significance
2000 by Prentice Hall. 4-19
Business Guidelines for Software Success (cont.)
Make or Buy? Off-the-shelf software has increased in both sophistication
and versatility Many times companies can customize off-the-shelf software
to meet unique information needs Develop Criteria for Software Investments That
Support Business Goals Using finances as the dominant criterion to make software
investment decisions has several limitations– encourages managers to manipulate numbers– difficult to accurately measure the monetary value of the software
system– hidden software costs are hard to estimate– different departments may use different methods to measure the
costs and benefits of software
2000 by Prentice Hall. 4-20
Business Guidelines for Software Success (cont.)
Remember That Software Is More Than Just Automation Software plays a key role in helping a company
maintain its corporate image or gain competitive advantage
Keep It Simple Software that is capable of performing complex
tasks and functions does not have to be complex Simple software is more affordable and easier for
people to learn and use
2000 by Prentice Hall. 4-21
Business Guidelines for Software Success (cont.)
Follow Software Development Guidelines Very few developers follow the guidelines
that are usually already in place Deviating from the guidelines produces high
development and maintenance costs Most developers are not paid to stick to
procedures; they are rewarded for getting projects done any way they can
2000 by Prentice Hall. 4-22
Business Guidelines for Software Success (cont.)
Pay Attention to Ethics If You Want Long-Term Profits The most important consideration is recognizing the
software copyright An organization can take steps to ensure that
employees do not violate copyright laws– Educate all employees and managers– Make one individual (or group) responsible for acquiring
software for the entire organization– Conduct regular audits of company software– Keep documentation related to the purchase, legal
ownership and registration of purchased software– Destroy illicit copies of software