Download Chapter 4

Chapter 4
Software: Systems &
Application Software
Software basics
 Software is a critical piece of making
computers perform
 Businesses typically spend more on software
than hardware
 Computer programs are sequences of
instructions for the computer
Chapter 4
2
IS for Management
Two broad classes of Software
 Systems Software
Set of programs that coordinate activities & functions
of the hardware & various other programs
 Application Software
Programs that help users solve particular computing
problems
Chapter 4
3
IS for Management
Software classified by “sphere of
influence”
Personal Information Software: Systems that serve
the needs of an individual user (e.g., wordprocessors,
databases, spreadsheets)
Workgroup Software: Systems that support two or more
people who work together to achieve a common goal (e.g.,
group scheduling, conferencing)
Enterprise Software: Systems that support the firm in its
interaction with its environment (e.g., order entry, billing)
Chapter 4
4
IS for Management
Software Issues & Trends
 Software Licensing
Protection by software vendors to prevent
unauthorized use
 Software Upgrades
A revised version of software that usually
includes fixes of known problems, plus
enhancements to existing capabilities
 Global Software Support
Software that is distributed around the globe
may require unique support mechanisms due to
local political & economic conditions
Chapter 4
5
IS for Management
Role of Systems Software
 Role of Systems Software
An interface or buffer between application
software & hardware
 Operating System
Controls the hardware & acts as an interface
with application programs
Chapter 4
6
IS for Management
Operating System Functions
 Perform common computer hardware functions
 Provide a user interface
 Provide a degree of hardware independence
 Manage system memory
 Manage processing tasks
 Provide networking capability
 Control access to system resources
 Manage files
Chapter 4
7
IS for Management
User Interfaces
 User Interface
A function of the operating system that allows
individuals to access & command the computer
Command-Based User Interface
Requires text commands to perform basic activities
Menu-Based User Interface
Requires pointing to menus & clicking on command
Graphical User Interface (GUI)
Uses pictures (icons) & menus displayed on the screen to send
commands to the computer system
Chapter 4
8
IS for Management
Software Concepts (1)
 Hardware Independence
Operating systems provide hardware
independence for application
software
The application software interfaces
with the operating system which Application
interfaces with the hardware
OS
Hardware
Chapter 4
9
IS for Management
Software Concepts (2)
 Memory Management
Controls how memory is accessed & maximizes
available memory & storage
 Virtual Memory
Memory that allocates space in secondary storage to
supplement the immediate, functional memory
capacity of RAM
 Paging
A function of virtual memory that allows the computer
to store currently needed pages in RAM while the rest
of these programs wait in secondary storage
Chapter 4
10
IS for Management
Software Concepts (3)
 Multitasking
A processing activity that allows a user to run more
than one application at the same time
 Multithreading
A processing activity that is basically multitasking
within a single application
 Time-sharing
A processing activity that allows more than one person
to use a computer system at the same time
Chapter 4
11
IS for Management
Software Concepts (4)
 Network capability
Aids in connecting the computer to a network
 Access to system resources
Provides security for unauthorized access
 File management
Ensures that files in secondary storage are available
when needed & are protected against unauthorized
usage
 Utility Programs
Merge & sort sets of data, keep track of computer jobs
being run, compress files of data before they are stored
or transmitted over a network, & perform other
important tasks
Chapter 4
12
IS for Management
Types of Application Software
 Proprietary Software
Designed to solve a unique & specific problem
Can be developed in-house or developed under
contract by an outside software provider
 Customized Software
Blend of in-house & external development
 Off-The-Shelf Software
An existing software program that can be used without
considerable changes expected
Chapter 4
13
IS for Management
Personal Application Software
 Word Processing Program
 Assistance in formulating, formatting, & printing documents such
as letters, memos, & papers
 Spreadsheet Program
 Built-in functions for statistical, financial, logical, database,
graphics, & data & time calculations
 Database Program
 Stores, manipulates, & retrieves data
 Software Suite
 Collection of personal productivity software such as word
processor, spreadsheet, & database
 Graphics Program
 Assistance in making presentations, developing brochures,
illustrations, etc.
 On-Line Services
 Provide access to various information resources
Chapter 4
14
IS for Management
Object Linking & Embedding
 Object Linking & Embedding (OLE) allows user
to copy text/graphics from one document to another
or to embed text/graphics from one program into
another program/document
 Server Application supplies objects user places in other
applications
 Client application accepts objects from other applications
 Copy copies data from one application & places it in
another
 Link is used when user wants changes made to the server
object to appear automatically in all linked client objects
 Embed is used when user wants an object to become part of
the client document
Chapter 4
15
IS for Management
Workgroup Application Software
 GroupWare
Helps groups of people work together more efficiently
& effectively
 Collaborative Computing Software
Helps teams of people work together toward a common
goal
Chapter 4
16
IS for Management
Enterprise Software
 Enterprise Application Software
Benefits the entire organization (e.g., accounts
receivable, accounts payable, general ledger, order
entry, etc.)
 Enterprise Resource Planning (ERP)
A set of integrated programs that manage a company’s
vital business operations for an entire multi-site, global
organization (e..g., SAP, PeopleSoft, J.D. Edwards,
Oracle, etc.)
Chapter 4
17
IS for Management
Programming Languages (1)
 Machine Language
The first generation programming language
A low-level language because it involves a basic coding
scheme using the binary symbols 1 & 0
 Assembly Language
Second generation language
Replaced binary digits with symbols programmers
could more easily understand
 Third Generation Languages
Continued trend to more symbolic code (e.g., COBOL,
FORTRAN)
Chapter 4
18
IS for Management
More Programming Languages
 Fourth Generation Languages (4GLs)
 Less procedural & even more English-like than third-generation
languages (e.g., FOCUS)
 Query Languages
 Ask the computer questions in English-like sentences (aka
database query languages)
 Structured Query Language (SQL)
Standardized query language used to perform database queries
& manipulations
Most modern database management system applications use or
support SQL
 Fifth-Generation Languages
 Combines rule-based code generation, component management,
visual programming techniques, & reuse management
Chapter 4
19
IS for Management
Object Oriented Languages
(Figure 4.17)
 Object Oriented Languages: Small Talk, C++,
Java
Chapter 4
20
IS for Management
Object Oriented Languages
 Object-Oriented Languages allow interaction of
programming objects, including data elements & the
actions that will be performed on them
 Encapsulation: The process of grouping items into an object
 Polymorphism: A process allowing the programmer to develop
one routine or set of activities that will operate on multiple objects
 Inheritance: Property used to describe objects in a group of
objects taking on characteristics of other objects in the same group
or class of objects
 Reusable Code: The instruction code within an object that can be
reused in different programs for a variety of applications
Chapter 4
21
IS for Management
Visual Programming Languages
 Visual Programming Languages
Use a mouse, icons, or symbols on the screen & pulldown menus to develop programs
Examples: Visual Basic, Visual C++, PC COBOL
 Knowledge-based Management Approach
User tells the computer what he/she wants the
computer to do rather than how to do the job
Chapter 4
22
IS for Management
Language Translation
Language translator: Systems software that
converts a programmer’s source code into its
equivalent in machine language
Interpreter: A language translator that translates one
program statement at a time into machine code
Compiler: A language translator that converts a
complete program into machine language to produce a
program that the computer can process in its entirety
Chapter 4
23
IS for Management
Case
 Gap uses object-oriented programming
pp. 184-185
 Next Class
Chapter 5 - Organizing data & information
Case: US West - Data warehousing
Chapter 4
24
IS for Management