Software: Systems and Application Software

1
Chapter 4

• Software Systems and Application Software

2
Agenda

• What is Software
• Overview of Software
• Operating Systems
• Popular Operating Systems
• Utility Programs
• Types of Application Software
• Proprietary Application Software
• Off-the-shelf Application Software
• Standard Off-the-shelf Application Software
• Software Issues and Trends
• Programming Languages
• Object Oriented Programming Languages
• Programming Language Selection
• Language Translators

3
What is Software

• Software consists of the computer programs that
  coordinate the workings of the computer hardware
  (statements to the computer) and the program
  documentation for explaining the operations of
  the programs to the user.

4
Overview of Software

• There are two basic types of software
• Systems Software is a set of programs to support
  the computer system by coordinating the
  activities of the hardware and the applications.
  Systems software is written for a specific set of
  hardware, most particularly the CPU.
• Application Software is a set of programs that
  solve specific user-oriented problems.

5
Operating Systems

• An Operating System is a set of computer programs
  that control the computer hardware and act as an
  interface with application programs.
• Operating System Activities
• Perform common computer hardware functions like
  storing data on disk
• Provide the user interface like the Windows XP
  Graphical User Interface or command-based user
  interface
• Provide hardware independence by serving as the
  interface between the application program and the
  hardware
• Manage system memory to control how memory is
  accessed and used
• Manage processing tasks like enabling the user to
  run more than one application (multitasking or
  time-sharing)
• Provide network capability to link users
• Control access to system resources by providing
  functions like password protection
• Manage files tracking where each file is stored
  and where is located

6
Popular Operating Systems

• Consumer Appliance Operating Systems
• Windows CE.Net/Windows XP/Handheld PC/Pocket PC
• Palm OS
• PC Operating Systems
• MS Windows 95/98/2000/XP
• Mac OS X
• Linux
• Network (workgroup) Operating Systems
• Windows 2000 Server
• Unix
• Netware
• Red Hat Linux
• Mac OS X Server
• Enterprise Operating Systems
• OS/390
• Linux

7
Utility Programs

• Utility programs are used to perform important
  functions like merging and sorting sets of data,
  keeping track of computer jobs and compressing
  files before they are stored.
• Examples of Utility programs
• DriveSpace compresses the hard drive increasing
  its storage capacity (Windows 95/98).
• Disk Defragmenter speeds up disk access by
  rearranging the files and free space on the
  computer (Windows 95/98)
• DFSORT sorts and merges data files (MVS)
• TestDrive allows trying the software before
  purchasing it and deleting the software from the
  hard drive after the trial period.
• Screen Saver
• Virus Detection

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Types of Application Software
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Proprietary Application Software

• Application Software gives organizations the
  ability to solve problems and perform specific
  activities and tasks.
• Proprietary application software solves a unique
  or specific problem.
• Proprietary application software can be In-house
  developed or developed by external vendors in
  which case is called contract software.
• Advantages of proprietary application software
• Software usually meets the user requirements
• Provides flexibility in making modifications
• Offers more control over the results
• Disadvantages of proprietary application
  software
• Can take a long time and significant resources to
  develop (costly)
• Has more risk concerning the features and
  performance

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Off-the-shelf Application Software

• Off-the-shelf application software may be
  purchased, leased, or rented from a software
  company. Off-the-shelf application software can
  be customized to better fit company specific
  needs.
• Advantages of Off-the-shelf application software
• Lower initial cost
• Lower risk that the software will fail
• Higher quality usually without bugs and well
  tested
• Disadvantages Off-the-shelf application software
• May pay for features never used
• May lack important features
• May not match current work processes

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Standard Off-the-shelf Application Software

• Personal Application Software
• Word processing
• Spreadsheet analysis
• Database applications
• Graphics programs
• On-line information services
• Software suites
• Workgroup Application Software
• Lotus Notes
• Group scheduling
• Enterprise Application Software

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Enterprise Resource Planning (ERP)

• ERP software a set of integrated programs that
  manage a companys critical business operations
• ERP software can support global operations so
  it must support many languages, legal entities,
  and currencies
• Examples
• SAP
• PeopleSoft
• Benefits
• Eliminate inefficient systems
• Improved data access for decision making
• Facilitate the adoption of improved work
  processes
• Supply chain management
• Costs
• Costly
• Changed business processes
• Employee resistance

13
Software Issues and Trends

• Software bugs and the costs associated with them
• Open Source Software can save you money but be
  aware of hidden costs
• Software Licensing
• Usage-based License
• Capacity-based License
• Software-as-a-network service
• Subscription Licensing
• Lack of tracking software licenses can cost the
  organization
• Software Publishers Association (SPA) can fine
  the organization 100,000 or more if it is caught
  with illegal software
• Software upgrades should be carefully evaluated
• Software support should be carefully evaluated
• Shareware and Freeware can save you money
• Shareware is the software where a user is
  expected to pay the author a modest amount
• Freeware is free software

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Programming Languages

• All software programs, both systems software and
  application software are written using
  programming languages
• The first generation Machine language (low level
  language)
• Written in binary code (0 and 1)
• Machine language is the language of the CPU
• The second generation Assembly language
• Replaces binary code with symbols understood by
  humans
• The third generation High-level languages (i.e.
  BASIC and COBOL)
• Translate each statement to many machine language
  instructions
• English-like, appropriate for certain types of
  applications
• Hardware independent
• The fourth generation 4GLs
• 4GLs have query and database abilities
• 4GLs have code-generation and graphics abilities
• Fifth generation
• Visual or graphical development interface to
  create source language

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Object Oriented Programming Languages

• Object-Oriented programming languages put data
  and action in an object and use message to allow
  the interaction between objects.
• Smalltalk (popular object-oriented language)
• C (enhancement of C to use the object-oriented
  approach)
• Java (allows programmers to develop applications
  that work across the Internet). Java code is
  embedded into the home page.

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Programming Language Selection

• Selecting the best programming language to use
  for a particular program involves balancing the
  functional characteristics of the language with
  cost, control and complexity issues.

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Language Translators

• Machine language is the only language capable of
  directly instructing the CPU. Every non machine
  language program instruction must be translated
  into machine language prior to execution.
  Language Translators convert high-level code into
  machine language.
• Interpreters translate one program statement at a
  time, as the program is running.
• Compilers translate a complete program into
  machine language, then the machine language is
  executed as needed. Because compiled programs run
  faster than programs that are translated line by
  line by an interpreter, programmers usually
  choose compilers to translate frequently run
  business programs.

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Points to Remember

• What is Software
• Overview of Software
• Operating Systems
• Popular Operating Systems
• Utility Programs
• Types of Application Software
• Proprietary Application Software
• Off-the-shelf Application Software
• Standard Off-the-shelf Application Software
• Software Issues and Trends
• Programming Languages
• Object Oriented Programming Languages
• Programming Language Selection
• Language Translators