E. Wainright Martin Carol V. Brown Daniel W. DeHayes Jeffrey A. Hoffer William C. Perkins MANAGINGINFORMATIONTECHNOLOGY FIFTH EDITION CHAPTER 3 C OMPUTER S OFTWARE

© 2005 Pearson Prentice-Hall Chapter Machine language (1GL) Each instruction must be expressed in unique form for a particular computer Complete program consists of thousands of instructions Programming was tedious, time-consuming process 2.Assembly languages (2GL)  Use computer itself to perform many aspects of the programming  Create a machine language program as output, that is then used by the computer’s control unit First and Second Generation Languages E VOLUTION OF C OMPUTER P ROGRAMMING Page 53

© 2005 Pearson Prentice-Hall Chapter First and Second Generation Languages E VOLUTION OF C OMPUTER P ROGRAMMING Page 53 Figure 3.1 Assembler Translation Process SOURCE PROGRAM OBJECT PROGRAM (which can be directly executed on computer)

© 2005 Pearson Prentice-Hall Chapter Procedural Languages (3GL) Generally are machine independent. Express a step-by-step procedure developed by programmer Must be compiled or interpreted (translated into machine language) Include FORTRAN, COBOL, BASIC, PL/1, PASCAL, ADA, and C Third and Fourth Generation Languages E VOLUTION OF C OMPUTER P ROGRAMMING Page 53

© 2005 Pearson Prentice-Hall Chapter Page 54 Figure 3.2 Compiling and Running a Procedural Language Program SOURCE PROGRAM OBJECT PROGRAM

© 2005 Pearson Prentice-Hall Chapter Page 54 Figure 3.3 Interpreting and Running an Interpretive Language Program SOURCE PROGRAM

© 2005 Pearson Prentice-Hall Chapter Nonprocedural Languages (4GL) Also referred to as productivity languages Use more English-like statements for program instructions Easier to use, write, and less error-prone Use a built-in interpreter to convert to machine language Take much longer to execute than 3GLs Include FOCUS, CA-Ramis, IFPS, and SAS Third and Fourth Generation Languages E VOLUTION OF C OMPUTER P ROGRAMMING Page 55

© 2005 Pearson Prentice-Hall Chapter Object-Oriented (Visual) Languages 3GLs with some 4GL features Built on idea of embedding procedures (methods) in objects, and putting objects together to create an application Include Smalltalk, C++, Java, and Visual Basic Third and Fourth Generation Languages E VOLUTION OF C OMPUTER P ROGRAMMING Page 55 Figure 3.4 The Software Iceberg

© 2005 Pearson Prentice-Hall Chapter Applications software 2.Support software Page 56 K EY T YPES OF S OFTWARE Figure 3.4 The Software Iceberg

© 2005 Pearson Prentice-Hall Chapter Spheres of Influence & Application Software Personal Workgroup Enterprise programs that serve the needs of an individual user word processing, spreadsheets, databases, programs that support the firm in its interaction with its environment order entry, billing Two or more people who work together to achieve a common goal Systems that support information sharing, group scheduling, group decision making, and conferencing

© 2005 Pearson Prentice-Hall Chapter Programs written to accomplish particular tasks Diverse … some general-purpose and some specific Examples include:  General ledger accounting  Portfolio management  Sales forecasting  Material requirements planning (MRP)  Electronic mail  Desktop publishing Page A PPLICATIONS S OFTWARE

© 2005 Pearson Prentice-Hall Chapter Peachtree Accounting Complete  Commercial accounting package for smaller businesses  Includes general ledger, accounts receivable, accounts payable, inventory, payroll, time and billing, job costing, fixed asset accounting, and analysis and reporting tools  $300 for single-user version Page 58 A PPLICATIONS S OFTWARE Examples of Applications Packages

© 2005 Pearson Prentice-Hall Chapter Page 58 Figure 3.5 “My Business Page” from Peachtree Complete Accounting

© 2005 Pearson Prentice-Hall Chapter Word processing Spreadsheets Presentation graphics Electronic mail and groupware Database management systems Desktop publishing Web browsers Statistical packages Page A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Word processing  Used to create documents for printing  Most popular is Microsoft Word  Others are Corel WordPerfect, Lotus Word Pro, and Sun’s StarOffice Writer  All employ WYSIWYG Page A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Spreadsheets  Used to create applications that fit a row-column format  Most popular is Microsoft Excel  Others are Lotus and Corel Quattro Pro  All employ rows, columns, cells, formulas, “what-if” analysis Page 60 A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Page 61 Figure 3.6 Microsoft Excel Spreadsheet

© 2005 Pearson Prentice-Hall Chapter Database Management Systems  Used to create databases similar to those on larger machines  Most popular is Microsoft Access  Others are FileMaker Pro, Corel Paradox, and Lotus Approach  All employ a relational data model Page 61 A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Presentation Graphics  Used to create largely textual business presentations  Most popular is Microsoft PowerPoint  Others are Corel Presentations and Lotus Freelance Graphics  All allow embedding of clip art, photos, graphs, and other media Page A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter World Wide Web Browsers  Used to access information on the Web  Requires ISP service to link PC to Internet  Create documents for printing  Most popular are Internet Explorer and Netscape Navigator … both free!  Both employ standard hypertext-based approach (way to link text and media objects to each other)  Use pull technology – browser requests a Web page before it is sent to desktop  Use push technology – data sent to client without requesting it (such as ) Page A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Electronic Mail  Preferred way of communicating in business today  Easy to use and precise Groupware  Incorporates and other productivity features, such as calendaring, scheduling, and document sharing Page 63 A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Office Suites  Popular software applications bundled together and sold as a single package (suite)  Used for home or office  Most popular is Microsoft Office  Others are Corel WordPerfect Office, Lotus SmartSuite, and Sun StarOffice Page 64 A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Page 64 A PPLICATIONS S OFTWARE Personal Productivity Software Microsoft Office 2003 EditionApplicationsPurposeRetail price Standard Word Excel PowerPoint Outlook Word processing Spreadsheets Presentation graphics , scheduling $399 Small Business Adds: Publisher Desktop publishing $449 Professional Adds: Access Database management $499

© 2005 Pearson Prentice-Hall Chapter User communicates with operating system software to control hardware and software resources Communication made easier with a graphical user interface (GUI) feature Page 66 S UPPORT S OFTWARE The Operating System Operating system – complex program that controls operation of computer hardware and coordinates other software

© 2005 Pearson Prentice-Hall Chapter Page 66 S UPPORT S OFTWARE The Operating System Job Control Language (JCL) – keyed instructions from the computer user to communicate with the operating system

© 2005 Pearson Prentice-Hall Chapter Page S UPPORT S OFTWARE The Operating System Multiprogramming – employed on larger machines to overlap input and output operations with processing time, keeping the CPU busy and speeding up execution Multitasking – similar to multiprogramming, but employed on microcomputers

© 2005 Pearson Prentice-Hall Chapter Virtual Memory  Concerned with management of main memory  Makes it appear more memory available than actually is  Used only on larger computers  Permits multiprogramming to operate more efficiently Page 67 S UPPORT S OFTWARE The Operating System

© 2005 Pearson Prentice-Hall Chapter Page 67 S UPPORT S OFTWARE The Operating System Multiprocessing – work that takes place when two or more CPUs are installed on same computer system

© 2005 Pearson Prentice-Hall Chapter Sources of Operating Systems  Microcomputers: MS-DOS, PC-DOS, Windows XP  Midrange systems: OS/400  Large systems: VM and MVS Page 68 S UPPORT S OFTWARE The Operating System Proprietary systems – most popular type of operating systems, written for a particular computer hardware configuration

© 2005 Pearson Prentice-Hall Chapter Sources of Operating Systems  Examples: UNIX and Linux Page 68 S UPPORT S OFTWARE The Operating System Open systems – not tied to any particular computer system or hardware manufacturer – will run on virtually any computer system

© 2005 Pearson Prentice-Hall Chapter Sources of Operating Systems  Enhanced operating system to allow for sharing disk drives and printers handling server side of client/server applications Page 68 S UPPORT S OFTWARE The Operating System Network operating systems (NOS) – software running on a server that manages network resources and controls the operation of a network

© 2005 Pearson Prentice-Hall Chapter Sources of Operating Systems Major players include: UNIX and Linux Microsoft Windows NT, 2000 Server, 2003 Server Novell NetWare Page 68 S UPPORT S OFTWARE The Operating System Network operating systems (NOS) – software running on a server that manages network resources and controls the operation of a network

© 2005 Pearson Prentice-Hall Chapter Procedural languages (3GL)  Require logical thinking  Entail development of a detailed step-by- step procedure  Can be developed using structured programming Page 69 S UPPORT S OFTWARE Third Generation Languages

© 2005 Pearson Prentice-Hall Chapter Advantages:  Program logic easier to follow  Maintenance and correction easier and faster  Do not use GO TO logic Page 70 S UPPORT S OFTWARE Third Generation Languages Structured programs – divided into modules, where each has one entry and one exit point

© 2005 Pearson Prentice-Hall Chapter Page 70 S UPPORT S OFTWARE Third Generation Languages Table 3.1 Stages in the Program Development Process

© 2005 Pearson Prentice-Hall Chapter Most popular procedural languages:  BASIC  C  COBOL Page S UPPORT S OFTWARE Third Generation Languages

© 2005 Pearson Prentice-Hall Chapter Page 71 Figure 3.9 BASIC Program

© 2005 Pearson Prentice-Hall Chapter Page 72 Figure 3.10 C Program

© 2005 Pearson Prentice-Hall Chapter Page 73 Figure 3.11 COBOL Program

© 2005 Pearson Prentice-Hall Chapter Page 73 Figure 3.11 COBOL Program

© 2005 Pearson Prentice-Hall Chapter Page 74 Figure 3.11 COBOL Program

© 2005 Pearson Prentice-Hall Chapter Other procedural languages:  FORTRAN  PL/1  PASCAL  ADA Page 74 S UPPORT S OFTWARE Third Generation Languages

© 2005 Pearson Prentice-Hall Chapter Nonprocedural languages:  Use very high-level instructions  Require fewer instructions  Easier to write, modify, understand  Example: FOCUS Page 75 S UPPORT S OFTWARE Fourth Generation Languages

© 2005 Pearson Prentice-Hall Chapter Page 76 Figure 3.12 FOCUS Program and Output

© 2005 Pearson Prentice-Hall Chapter Most popular:  HTML: used to create Web pages  XML: used to facilitate data interchange among Web applications Page S UPPORT S OFTWARE Markup Languages

© 2005 Pearson Prentice-Hall Chapter Requires more computing power Has built-in GUI Neither 3GL nor 4GL … new paradigm Creates objects only once and stores for reuse Object examples:  Text box, check box, entity in an organization Languages:  Smalltalk, C++, Java, Visual Basic.NET Page 78 S UPPORT S OFTWARE Object-Oriented Programming

© 2005 Pearson Prentice-Hall Chapter Page 80 Figure 3.13A Visual Basic Program

© 2005 Pearson Prentice-Hall Chapter Page 81 Figure 3.13B Visual Basic Screen Layout

© 2005 Pearson Prentice-Hall Chapter HTML Server-side programming languages:  Perl  Java Servlets and Java Server Pages  Microsoft Active Server Pages (ASP, ASP.NET)  ColdFusion Page S UPPORT S OFTWARE Languages for Developing Web Applications

© 2005 Pearson Prentice-Hall Chapter Page 84 Figure 3.17 Grocery Store HTML Form

© 2005 Pearson Prentice-Hall Chapter Page 85 Figure 3.17 HTML and ASP.NET code to accompany Grocery Store HTML Form

© 2005 Pearson Prentice-Hall Chapter Page 86 Figure 3.18 Program to Process Data from Grocery Store HTML Form

© 2005 Pearson Prentice-Hall Chapter Page 86 Figure 3.19 Grocery Store Confirmation Web Page

© 2005 Pearson Prentice-Hall Chapter Page 86 Figure 3.19 Code to Generate Confirmation Web Page

© 2005 Pearson Prentice-Hall Chapter DBMS – support software used to create, manage, and protect organizational data Database – shared collection of logically related data organized to meet organizational needs Relational DBMS  Most common type  Data arranged in simple tables  Records related by storing common data in each associated table  Examples: Microsoft Access and SQL Server, Paradox, DB2, and Ingres Page 87 S UPPORT S OFTWARE Database Management Systems

© 2005 Pearson Prentice-Hall Chapter Sequential – arranges records physically adjacent and in order by some (usually unique) sort key Direct – uses key for records placed so that they are rapidly accessed from DASDs Page 88 S UPPORT S OFTWARE File Organization Figure 3.20 File Organizations

© 2005 Pearson Prentice-Hall Chapter S UPPORT S OFTWARE Indexed  Compromise between sequential and direct  Record keys only arranged in sequence in a separate table, along with location of rest of data associated with that key  Popular types include ISAM and VSAM Page 88 File Organization Figure 3.20 File Organizations

© 2005 Pearson Prentice-Hall Chapter Page 89 Figure 3.21 Relationship Schemes Relational DBMSs use this scheme

© 2005 Pearson Prentice-Hall Chapter  Growth slower than anticipated  Radically changed nature of systems analyst and programmer jobs Page 88 S UPPORT S OFTWARE CASE Tools Computer-aided software engineering (CASE) – collection of software tools to help automate all phases of the software development life cycle

© 2005 Pearson Prentice-Hall Chapter Large computers  need to control workstations and terminals  Example software: IBM’s CICS, TSO, and CMS LANs and WANs  Need to connect to the Internet  Web browsers  Telenet  File Transfer Protocol (FTP) Page S UPPORT S OFTWARE Communications Interface Software

© 2005 Pearson Prentice-Hall Chapter More complexity of hardware/software arrangements Less concern with machine efficiency More purchased applications More programming using object-oriented and visual languages More emphasis on applications that run on intranets and the Internet More user development More use of personal productivity software Page T HE C HANGING N ATURE OF S OFTWARE

© 2005 Pearson Prentice-Hall Chapter More complexity of hardware/software arrangements Less concern with machine efficiency More purchased applications More programming using object-oriented and visual languages More emphasis on applications that run on intranets and the Internet Page 92 T HE S OFTWARE C OMPONENT OF THE I NFORMATION S YSTEMS I NDUSTRY

© 2005 Pearson Prentice-Hall Chapter Trends in Computer Software User-written programs Machine languages Packaged programs Symbolic languages Operating systems High-level languages DBMS Fourth-generation languages Microcomputer packages Natural & object- oriented languages Multipurpose graphic-interface network-enabled expert-assisted packages Trend: Toward Easy-to-Use Multipurpose Network-Enabled Application Packages for Productivity and Collaboration Trend: Toward Visual or Conversational Programming Languages and Tools

Porter’s Five Forces Model

UAL was the first airline to offer a competitive advantage with its frequent flyer mileage

An example of an organization with “ high ” supplier power