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

2.  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

3.  2000 by Prentice Hall.4-3 The Two Main Types of Software Performs basic functions to start a computer Controls, coordinates, and manages all computer-related resources System Software Automates and performs different functions like payroll, inventory, and sales analysis Application Software Software

4.  2000 by Prentice Hall.4-4 The Three Major Categories of System Software Software TypeDescription 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

5.  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 system resources Resource Management Load programs and files into memory Read, create, and do related tasks with files File Management OPERATING SYSTEM FUNCTIONS Help users interface with computers Select and manage input/output devices and application programs Resolve and track errors, conflicts, and security features Manage multitasking User Management

6.  2000 by Prentice Hall.4-6 Operating System Environments EnvironmentDescription 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

7.  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

8.  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

9.  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

10.  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

11.  2000 by Prentice Hall.4-11 Application Software  Software designed to perform people-related tasks such as payroll, inventory, and sales analysis.

12.  2000 by Prentice Hall.4-12 Five Types of General-Purpose Application Software Type of Application Software 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

13.  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.

14.  2000 by Prentice Hall.4-14 Application-Dedicated Software  Specialized or customized software designed to meet specific information needs of users.

15.  2000 by Prentice Hall.4-15 Different Generations of Software Programming Languages Generation of Language 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

16.  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.

17.  2000 by Prentice Hall.4-17 Visual Programming  Programming languages that allow users to visualize their code and its impact on the system.

18.  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

19.  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

20.  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

21.  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

22.  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