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Chapter 4 IS for Management2
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 IS for Management3
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 IS for Management4
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 IS for Management5
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 IS for Management6
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 IS for Management7
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 IS for Management8
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 IS for Management9
Software Concepts (1)
Hardware Independence Operating systems provide hardware
independence for application software The application software interfaces with
the operating system which interfaces with the hardware
OS
Hardware
Application
Chapter 4 IS for Management10
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 IS for Management11
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 IS for Management12
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 IS for Management13
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 IS for Management14
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 IS for Management15
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 IS for Management16
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 IS for Management17
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 IS for Management18
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 IS for Management19
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 IS for Management20
Object Oriented Languages(Figure 4.17)
Object Oriented Languages: Small Talk, C++, Java
Chapter 4 IS for Management21
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 IS for Management22
Visual Programming Languages
Visual Programming Languages Use a mouse, icons, or symbols on the screen & pull-down 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 IS for Management23
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