ch4 software
TRANSCRIPT
Information System for Managers
Chapter 4 - Software: Systems and Application Software
CONTENT
Why Learn about S/WIntroductionSystem Software
Operating System Utility Programs Middleware and Others
Application SoftwareProgramming LanguagesOpen Source Software
Why Learn About Software?
Systems & application S/W are critical in helping individuals & organizations achieve their goals
Decide – Build or BuyChoose appropriate software platform
considering the skills and experienceNeed to be aware of recent trends and issues to
be effective in business and personal life
Introduction
Systems software: coordinates the activities and functions of hardware and programs
Computer system platform: combination of a hardware configuration and systems software
Application software: helps users solve particular problems
Computer programs: sequences of instructions for the computer
Documentation: describes program functions
Systems Software
Operating systemsUtility programsMiddleware and Others
Operating Systems (continued)
Combinations of OSs, computers, and users Single computer with a single user, e.g. PC Single computer with multiple users, e.g. Main Frame
computer where hundreds of users are working Multiple computers, e.g. network of computers Special-purpose computers, e.g. home appliances
Operating Systems (continued)
OS is set of programsActivities performed by the operating system
Perform common computer hardware functions Provide a user interface and input/output
management Provide a degree of hardware independence Manage system memory Manage processing tasks Provide networking capability Control access to system resources Manage files
Operating Systems (continued)
Figure 4.4: The Role of Systems Software
Operating Systems (continued)
Common hardware functions Get input from keyboard or some other input device Retrieve data from disks Store data on disks Display information on a monitor or printer
Operating Systems (continued)
User interface and input/output management User interface: allows individuals to access and
command the computer system Command-based user interface: requires that text
commands be given to the computer to perform basic activities
Graphical user interface (GUI): uses icons and menus displayed on screen to send commands to the computer system
Operating Systems (continued)
Hardware independence Application program interface (API): allows
applications to make use of the operating system If hardware changes, application software need not
change
Memory management Control how memory is allocated, accessed and
maximize available memory and storage Physical Memory vs. Virtual Memory
Operating Systems (continued)
Figure 4.6: Application Program Interface Links Application Software to the Operating System
Processing tasks Multitasking: more than one program can run at the
same time Time-sharing: allows more than one person to use a
computer system at the same time Scalability: ability of the computer to handle an
increasing number of concurrent users smoothly
Networking capability Features and capabilities of the OS that aid users in
connecting to a computer network
Operating Systems (continued)
Operating Systems (continued)
Access to system resources and security Protection against unauthorized access Logins and passwords
File management Ensures that files in secondary storage are available
when needed and that they are protected from access by unauthorized users
Current OS
Table 4.2: Popular Operating Systems Cross All Three Spheres of Influence
Current OS (cont)
Microsoft PC operating systems PC-DOS and MS-DOS: early, command-driven OSs Windows XP: greatly improved stability and security
over previous versions of Windows Windows XP Professional X64: for computers with
newer 64-bit capabilities Vista: latest version of Windows Which is the new OS already announced?
Current OS (cont)
Apple operating systems Often provide cutting edge tools in graphics and
music not available from Microsoft Mac OS X
Jaguar (OS X.2) Panther (OS X.3) Tiger (OS X.4): support for 64-bit computing,
Dashboard, Spotlight, etc.
Current OS (cont)
Linux Developed by Linus Torvalds in 1991 Open-source product Only the kernel of an OS Several distributions available with
capabilities/applications that form a complete OS Examples: Red Hat Linux, Caldera OpenLinux
Workgroup Operating Systems
Windows ServerUNIXNetWareRed Hat LinuxMac OS X Server
Enterprise Operating Systems
z/OSMPE/iXHP-UXLinux
Operating Systems for Small Computers, Embedded Computers,
and Special-Purpose Devices
Palm OSWindows EmbeddedWindows Mobile
Utility Programs
Hardware utilities: i.e. check status of Hard DiskVirus-detection and recovery utilitiesFile-compression utilitiesSpam and pop-up blocker utilitiesNetwork and Internet utilitiesServer and mainframe utilities
Monitor network Virtual Machine – Multiple OS on same machine
Other utilities, e.g. Searches for files and documents
Middleware and Others
Middleware: Software that allows different applications to communicate & exchange data.
WEB Server (e.g. Apache)Application Server (WEBSphere)Transaction Server (Tuxedo)RDBMS (SQL Server 2005)CompilersInterpreters
Application Software
Primary function is to apply the power of the computer to give individuals, workgroups, and the entire enterprise the ability to solve problems and perform specific tasks, e.g.
Railway Reservation ATM Pay Roll
Application programs interact with systems software; systems software then directs computer hardware to perform the necessary tasks
Overview of Application Software
Proprietary software: one-of-a-kind program for a specific application, usually developed and owned by a single company, e.g. Pay Roll for Krune Computer Consultancy
Off-the-shelf software: existing software program that is purchased, e.g. Tally
Overview of Application Software (continued)
Table 4.4: A Comparison of Proprietary and Off-the-Shelf Software
Overview of Application Software (continued)
Table 4.4: A Comparison of Proprietary and Off-the-Shelf Software (continued)
Personal Application Software
Serves the needs of an individual userIncludes personal productivity software
Enables users to improve their personal effectiveness
Personal Application Software (continued)
Table 4.5: Examples of Personal Productivity Software
Personal Application Software (continued)
Table 4.5: Examples of Personal Productivity Software (continued)
Personal Application Software (continued)
Software suite: collection of single application programs packaged in a bundle
Microsoft Office: most popular general-purpose software suite
Other general-purpose software suites: Corel’s WordPerfect Office, Lotus SmartSuite, Sun Microsystems’s StarOffice
Integrated application packages: offer a range of capabilities for less money than software suites
Example: Microsoft Works
Personal Application Software (continued)
Table 4.6: Major Components of Leading Software Suites
Workgroup Application Software
Workgroup application software: support teamwork, whether people are in the same
location or dispersed around the world Helps groups of people work together more efficiently
and effectivelyExamples Schedule Team Meetings – reflects on individual
calendar Collaborative software for working on same
document, e.g. Track Change Threaded group discussion
Enterprise Application Software
Software that benefits an entire organization
Enterprise Application Software
Enterprise resource planning (ERP) software: set of integrated programs that manage a company’s vital business operations for an entire multisite, global organization
Specialized Application Software Forecasting sale for next month Predicting which customer is more likely to buy Which items in supermarket sell together Visualize and analyze the human genome
Programming Languages
Sets of keywords, symbols, and a system of rules for constructing statements by which humans can communicate instructions to be executed by a computer
Different languages have different characteristics
Syntax: a set of rules associated with a programming language
The Evolution of Programming Languages
3G Example – C, COBOL, FORTRAN Table 4.9: The Evolution of Programming Languages
3GL Vs 4GL
3GL Tells how to do More Efficient More flexible
4GL Tells what to do (How part left on system) Higher productivity
Embedding 4GL in 3GL – Best of both worlds3GL Object oriented programming languages
are based on objects, e.g. C++, Java
The Evolution of Programming Languages (continued)
Figure 4.21: Reusable Code in Object-Oriented Programming
Complier and Interpreter
Compiler: a special software program that converts programmer’s source code into machine-language program
Interpreter: a special software program that converts programmer’s instruction (One at a time) into machine-language instructions and executes them
The Evolution of Programming Languages (continued)
Figure 4.23: How a Compiler Works
Software Issues and Trends
Because software is such an important part of today’s computer systems, software issues have received increased attention
Major software issues and trends discussed in the text
Software bugs, copyright, software licensing, open-source software, shareware and public domain software, multiorganizational software development, software upgrades, and global software support
Software Issues and Trends (Cont)
Software bug: defect in a computer program that keeps it from performing as it is designed to perform
Most software products are protected by law using copyright or licensing provisions
In some cases, you are given unlimited use of software on one or two computers
In other cases, you pay for your usage—if you use the software more, you pay more
Some software now requires that you register or activate it before it can be fully used
Open-Source Software
Open-source software: software freely available to anyone in a form that can
be easily modified (System Software, Utility or Application Software)
Some widely used open-source software: Linux OS, Free BSD, Apache, Sendmail, Perl
Open-source software disadvantages systems can contain hidden costs, particularly for
user support or solving problems with the software However community or paid third party support made
available
Open-Source Software (continued)
Table 4.10: Examples of Open-Source Software
Shareware, Freeware, and Public Domain Software
Shareware and freeware: Software that is very inexpensive or free Source code cannot be modified Source code may not be available (Acrobat Reader)
Public domain software: Shareware and freeware that is in the public domain Not protected by copyright law Can be freely copied and used May not be open source
Open Source Source is available
Software Upgrades
Software companies revise their programs and sell new versions periodically
Revised software may or may not offer any major additional capabilities
Revised software may have patches for bugsRevised software can contain bugs or errors
Users should not be first to work at the latest version Who should be first?
Software upgrades usually cost much less than the original purchase price
Global Software Support
Vendors face the challenge of providing adequate support for their software customers in all locations of the world
Trend of outsourcing global support to one or more third-party distributors