Chapter 4 Uma Gupta Introduction to Information Systems 2000 by Prentice Hall. 4-1 Computer Software

2000 by Prentice Hall. 4-1

Chapter 4

Uma GuptaIntroduction to Information Systems

Computer Software


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


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


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


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


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


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


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



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



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


Application Software

Software designed to perform people-related tasks such as payroll, inventory, and sales analysis.


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


General-Purpose Software

Software mass produced for a broad range of common business applications such as word processing, graphics, payroll, and accounting.


Application-Dedicated Software

Specialized or customized software designed to meet specific information needs of users.


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


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.


Visual Programming

Programming languages that allow users to visualize their code and its impact on the system.


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


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



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



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



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

Documents

Chapter 4 Uma Gupta Introduction to Information Systems 2000 by Prentice Hall. 4-1 Computer Software