1. CHAPER 4 COMPUTER SOFTWARE Oleh : Kundang K Juman

2. Learning Objectives
Differentiate between the two major types of software
Describe the general functions of the operating system
Differentiate among the three types of operating systems and describe each type
Identify three methods for developing application software
Describe the major types of application software
Explain how software has evolved and its future evolution
Describe enterprise software

3. Chapter Overview Software History and Significance The Software
Crisis
Software
Fundamentals
Systems
Software
System Control
Programs
System Support
Application
Software
Types of Application Software
Types of Personal Application
Software Suites
Software
Issues
evaluation and
Selection
Software Licensing
Software Upgrades
Shareware,
Freeware, and
Cheapware
Open Systems
Programming Languages
Machine Language
Assembly Language
Procedural Languages
Nonprocedural Languages
Natural Programming Language
Visual Programming Language
Hypertext Markup Language
Virtual Reality Modelling Language
Object-Oriented Programming
Language
Enterprise
Software
Streamlining
Organizational
SAP

4. Case: The IRS and the Millennium Bug
The Problem
Y2K problem has resulted from the high cost of mainframe computations and data storage in the 1950s and 1960s
complex structure makes it almost impossible for the IRS to be Y2K compliant in time
agency changed its software in response to changes in the tax code

5. Case (continued…) The Solution The Results
IRS has spent more than $4 billion over the past decade to modernize its computer systems
the agency has $1 billion dollars and 600 people dedicated to the Y2K project
The Results
no one will know until well into the year 2000

6. Case (continued…) What have we learned from this case??
Failure to budget for continuing maintenance of software programs can have devastating results
One programmer cannot begin with his portion of the problem until he receives another completed portion form someone else, as this other part or “module” may define the inputs or outputs that his own part must deal with

7. Software History and Significance
When the first applications of computers in business were introduced in the early 1950s, software was less important (and less costly) in computer systems
Today, software comprises a much larger percentage of the cost of modern computer systems
The Software Crisis
no software applications fast enough to keep up with rapidly changing business conditions and rapidly evolving technologies
not only must new applications be developed quickly, but existing software must also be maintained
increasing complexity, leads to the increased potential for “bugs”
testing and “debugging” software is expensive and time-consuming

8. Software History and Significance (continued …)
Software Fundamentals
computer programs - sequences of instructions for the computer
programming - process of writing (or coding) programs
programmers - individuals who perform programming

9. System Software System software
the class of programs that control and support the computer system and its information processing activities
facilitates the programming, testing, and debugging of computer programs
usually independent of any specific type of application
support application software by directing the basic functions of the computer

10. System Software (continued …)
System Control Program
programs that control the use of the hardware, software and data resources of a computer system
operating system (main system control program)
supervises the overall operation of the computer, including monitoring the computer’s status and scheduling operations, which include controlling the input and output processes
allocates CPU time and main memory to programs running on the computer, and also provides an interface between the user and the hardware

11. System Software (continued …)
System Control Program (continued …)
Process management
managing the program or programs running on the processor at a given time
Multitasking (or multiprogramming)
managing two or more tasks, programs, running on the computer system at the same time
Time-sharing
a number of users operate on-line with the same CPU, but each uses a different input/output terminal

12. System Software (continued …)
System Control Program (continued …)
Multithreading
a form of multitasking that focuses on running multiple tasks within a single application simultaneously
Multiprocessing
a computer system with two or more processors that can run more than one program or thread at a given time by assigning them to different processors
Virtual memory
simulates more main memory than actually exists in the computer system

13. System Software (continued …)
System Control Program (continued …)
File Management and Security
managing the arrangement of, and access to, files held in secondary storage
Fault Tolerance
the ability of a system to produce correct results and continue to operate even in the presence of faults or errors
Graphical User Interface (GUI)
allows users to have direct control of visible objects and actions that replace complex command syntax

14. System Software (continued …)
System Control Program (continued …)
Major Desktop Operating Systems
MS-DOS
Windows 3.xx
Windows 98
Windows 95
Windows NT
Windows 2000
Windows CE
IBM’s OS/2
Macintosh Operating System
UNIX
Java Operating System (JavaOS)

15. System Software (continued …)
System Control Program (continued …)
Major Departmental Sever Operating System
UNIX, Windows NT Server, IBM’s OS/2 Warp Server, Novell NetWare, and IBM’s OS/400
Major Enterprise Operating Systems
IBM’s MVS (Multiple Virtual Storage), IBM’s VM (Virtual Machine), IBM’s VSE (Virtual Storage Extended), and Digital Open VMS (Virtual machine System)

16. System Software (continued …)
System Support Programs
System support programs
support the operations, management, and users of a computer system
System utility programs
accomplish common tasks such as sorting records, checking the integrity of diskettes, creating directories and subdirectories, restoring accidentally erased files, locating files within the directory structure, managing memory usage, and redirecting output

17. System Software (continued …)
System Support Programs (continued …)
System performance monitors
monitor the processing of jobs on a computer system and produce reports containing detailed statistics concerning the use of system resources
System security monitors
monitor the use of a computer system to protect it and its resources from unauthorized use, fraud, or destruction

18. Application Software Application Software
instructions that direct a computer system to perform specific information processing activities and provide functionality for users
Types of Application Software
Proprietary application software
addresses a specific or unique business need for a company
Off-the-shelf application software
developed programs sold to many organizations
may be customizable or may be standard package

19. Application Software (continued …)
Personal Application Software
one of the off-the-shelf application programs that are not linked to any specific business function, but instead support general types of processing
Data management
Encompassing spreadsheet
Desktop publishing
Publishing
Word processing
Communications
Graphics
Multimedia
GroupWare
Speech recognition software

20. Application Software (continued …)
Software Suites
collections of application software packages that integrate the functions of the packages
examples : Microsoft Office, Novell Perfect Office, and Lotus SmartSuite
generally include : a spreadsheet program, word processor, database program, and graphics package with the ability to move document, data. And diagrams among them

21. Software Issues Software Selection Selection factors
size and location of the current and future user base
system administration tools
initial and subsequent costs
current and future system capabilities
existing computing environment
in-house technical skills

22. Software Issues (continued …)
Software Evaluation
evaluation checklist
ease of use in development
learning
maintenance
reporting capability
graphic presentation
general functionality
data handling
output options
performance
security
environments and hardware
documentation
vendor support

23. Software Issues (continued …)
Software Licensing
copyright - exclusive legal right to reproduce, publish, and sell the software
licenses - permission granted under the law to engage in an activity otherwise unlawful
Software Upgrades
revised software may offer valuable enhancements but may offer little in terms of additional capabilities
revised software may contain bugs

24. Software Issues (continued …)
Shareware, Freeware, and Cheapware
Shareware - low price software
Freeware - free copyrighted software
Cheapware - free public-domain software
Open Systems
a paradigm of computing products that work together
use the same operating system with compatible software on all the different computers in a system
to empower designers to choose the best computer hardware, operating system, and application software

25. Programming Languages
Machine Language (first generation of programming languages)
the lowest level computer language
composed of binary digits
all other languages are translated into machine language before the computer can run the instructions
Assembly Language (second generation of computer languages)
a lower-level but more user-friendly language
assembler - translates an assembly language program into machine language
… .. ……

26. Programming Languages (continued …)
Procedural Languages (third generation languages)
much closer to natural language
use common words rather than abbreviated mnemonics
compiler - translates the entire program at once
interpreter - translates and executes one source program statement at a time

27. Programming Languages (continued …)
Nonprocedural Language (fourth generation languages)
a high-level language
allows the user to specify the desired result without having to specify the detailed procedures needed for achieving the result
can be used by non technical users
Natural Language programming Languages (fifth generation languages)
translates natural languages into a structured, machine-readable from are extremely complex

28. Programming Languages (continued …)
Visual Programming Languages
used within a graphical environment
example : Visual Basic and Visual C++
popular to non technical users
Hypertext Markup Language (HTML)
standard language used in World Wide Web
contains text, images, and other types of information such as data files, audio, video, and executable computer programs

29. Programming Languages (continued …)
Virtual Reality Modeling Language (VRML)
a file format for describing three-dimensional interactive worlds and objects
can be used with the World Wide Web
Object-Oriented Programming Languages (OOP)
based on the idea of taking a small amount of data and the instructions about what to do with that data and putting both of these together into what is called an object

30. Enterprise Software Difficulty in Most Organizations
the sheer complexity that arises from all the different types of hardware and software that they use
Package Wanted by an Organization
support integration between functional (i.e., human resource, operations, marketing, finance, accounting, etc.) modules
be quickly changed or enhanced
present a common graphical look-and-feel
help to reduce training and operation costs

31. Enterprise Software (continued …)
manages a company’s vital operations, such as supply chain management (movement of raw material from suppliers through shipment of finished goods to customers), inventory replenishment, ordering, logistics coordination, human resource management, manufacturing, operations, accounting, and financial management

32. Enterprise Software (continued …)
System Anwendung Produket (SAP)
one of the largest vendors (holds 30% of the enterprise software market)
strength :  high degree of integration  support for multi-site, multi-currency operations
R / 3 - flagship client/server product
has a high degree of functional integration across the enterprise
criticism : complex, time-consuming and expensive to install and integrate with other systems
decoupling the models of R/3 into separate components, each with its own database