1 Introduction to Information Technology Turban Rainer and

1 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software CHAPER 4 COMPUTER SOFTWARE Oleh : Kundang K Juman

2 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software 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 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Chapter Overview Software History and Significance • The Software Crisis • Software Fundamentals Software Issues Systems Software • System Control Programs • System Support Programs Programming Languages Application Software • Types of Personal Application Software • Software Suites Enterprise Software • Software evaluation and Selection • Software Licensing • Software Upgrades • Shareware, Freeware, and Cheapware • Open Systems • Machine Language • Streamlining • Assembly Language Organizational • Procedural Languages Software • Nonprocedural Languages • SAP • Natural Programming Language • Visual Programming Language • Hypertext Markup Language • Virtual Reality Modelling Language • Object-Oriented Programming Language

4 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Case: The IRS and the Millennium Bug The Problem îY 2 K problem has resulted from the high cost of mainframe computations and data storage in the 1950 s and 1960 s îcomplex structure makes it almost impossible for the IRS to be Y 2 K compliant in time îagency changed its software in response to changes in the tax code

5 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Case (continued…) The Solution îIRS has spent more than $4 billion over the past decade to modernize its computer systems îthe agency has $1 billion dollars and 600 people dedicated to the Y 2 K project The Results îno one will know until well into the year 2000

6 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Case (continued…) What have we learned from this case? ? îFailure to budget for continuing maintenance of software programs can have devastating results îOne 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 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software History and Significance When the first applications of computers in business were introduced in the early 1950 s, 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 î no software applications fast enough to keep up with rapidly changing business conditions and rapidly evolving technologies î not only must new applications be developed quickly, but existing software must also be maintained î increasing complexity, leads to the increased potential for “bugs” î testing and “debugging” software is expensive and timeconsuming

8 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software History and Significance (continued …) Software Fundamentals îcomputer programs - sequences of instructions for the computer îprogramming - process of writing (or coding) programs îprogrammers - individuals who perform programming

9 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software System software îthe class of programs that control and support the computer system and its information processing activities îfacilitates the programming, testing, and debugging of computer programs îusually independent of any specific type of application îsupport application software by directing the basic functions of the computer

10 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software System Software (continued …) System Control Program îprograms that control the use of the hardware, software and data resources of a computer system îoperating 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 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software System Software (continued …) System Control Program (continued …) îProcess management » managing the program or programs running on the processor at a given time îMultitasking (or multiprogramming) » managing two or more tasks, programs, running on the computer system at the same time îTime-sharing » a number of users operate on-line with the same CPU, but each uses a different input/output terminal

12 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software System Software (continued …) System Control Program (continued …) îMultithreading » a form of multitasking that focuses on running multiple tasks within a single application simultaneously îMultiprocessing » 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 îVirtual memory » simulates more main memory than actually exists in the computer system

13 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software System Software (continued …) System Control Program (continued …) îFile Management and Security » managing the arrangement of, and access to, files held in secondary storage îFault Tolerance » the ability of a system to produce correct results and continue to operate even in the presence of faults or errors îGraphical User Interface (GUI) » allows users to have direct control of visible objects and actions that replace complex command syntax

14 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software System Software (continued …) System Control Program (continued …) îMajor 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 (Java. OS)

15 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software System Software (continued …) System Control Program (continued …) îMajor Departmental Sever Operating System » UNIX, Windows NT Server, IBM’s OS/2 Warp Server, Novell Net. Ware, and IBM’s OS/400 îMajor 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 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software System Software (continued …) System Support Programs îSystem support programs » support the operations, management, and users of a computer system îSystem 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 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software System Software (continued …) System Support Programs (continued …) îSystem performance monitors » monitor the processing of jobs on a computer system and produce reports containing detailed statistics concerning the use of system resources îSystem security monitors » monitor the use of a computer system to protect it and its resources from unauthorized use, fraud, or destruction

18 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Application Software îinstructions that direct a computer system to perform specific information processing activities and provide functionality for users Types of Application Software îProprietary application software » addresses a specific or unique business need for a company îOff-the-shelf application software » developed programs sold to many organizations » may be customizable or may be standard package

19 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Application Software (continued …) Personal Application Software îone of the off-the-shelf application programs that are not linked to any specific business function, but instead support general types of processing Encompassing spreadsheet Desktop publishing Graphics Data management Publishing Multimedia Speech recognition software Word processing Communications Group. Ware

20 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Application Software (continued …) Software Suites îcollections of application software packages that integrate the functions of the packages îexamples : Microsoft Office, Novell Perfect Office, and Lotus Smart. Suite îgenerally include : a spreadsheet program, word processor, database program, and graphics package with the ability to move document, data. And diagrams among them

21 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Issues Software Selection îSelection 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 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Issues (continued …) Software Evaluation îevaluation checklist » ease of use in development » maintenance » graphic presentation » data handling » performance » environments and hardware » vendor support » learning » reporting capability » general functionality » output options » security » documentation

23 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Issues (continued …) Software Licensing îcopyright - exclusive legal right to reproduce, publish, and sell the software îlicenses - permission granted under the law to engage in an activity otherwise unlawful Software Upgrades îrevised software may offer valuable enhancements but may offer little in terms of additional capabilities îrevised software may contain bugs

24 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Issues (continued …) Shareware, Freeware, and Cheapware îShareware - low price software îFreeware - free copyrighted software îCheapware - free public-domain software Open Systems îa paradigm of computing products that work together îuse the same operating system with compatible software on all the different computers in a system îto empower designers to choose the best computer hardware, operating system, and application software

25 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Programming Languages Machine Language (first generation of programming languages) …. . îthe lowest level computer language …… îcomposed of binary digits îall other languages are translated into machine language before the computer can run the instructions Assembly Language (second generation of computer languages) îa lower-level but more user-friendly language îassembler - translates an assembly language program into machine language

26 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Programming Languages (continued …) Procedural Languages (third generation languages) îmuch closer to natural language îuse common words rather than abbreviated mnemonics îcompiler - translates the entire program at once îinterpreter - translates and executes one source program statement at a time

27 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Programming Languages (continued …) Nonprocedural Language (fourth generation languages) îa high-level language îallows the user to specify the desired result without having to specify the detailed procedures needed for achieving the result îcan be used by non technical users Natural Language programming Languages (fifth generation languages) îtranslates natural languages into a structured, machinereadable from are extremely complex

28 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Programming Languages (continued …) Visual Programming Languages îused within a graphical environment îexample : Visual Basic and Visual C++ îpopular to non technical users Hypertext Markup Language (HTML) îstandard language used in World Wide Web îcontains text, images, and other types of information such as data files, audio, video, and executable computer programs

29 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Programming Languages (continued …) Virtual Reality Modeling Language (VRML) îa file format for describing three-dimensional interactive worlds and objects îcan be used with the World Wide Web Object-Oriented Programming Languages (OOP) îbased 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 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Enterprise Software Difficulty in Most Organizations îthe sheer complexity that arises from all the different types of hardware and software that they use Package Wanted by an Organization îsupport integration between functional (i. e. , human resource, operations, marketing, finance, accounting, etc. ) modules îbe quickly changed or enhanced îpresent a common graphical look-and-feel îhelp to reduce training and operation costs

31 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Enterprise Software (continued …) Enterprise Software îmanages 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 Introduction to Information Technology Turban, Rainer and Potter Chapter 4 Computer Software Enterprise Software (continued …) System Anwendung Produket (SAP) îone of the largest vendors (holds 30% of the enterprise software market) îstrength : high degree of integration support for multi-site, multi-currency operations îR / 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