1. MANAGINGINFORMATIONTECHNOLOGY CHAPTER 3 C OMPUTER S OFTWARE

2. 1.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

3. First and Second Generation Languages E VOLUTION OF C OMPUTER P ROGRAMMING SOURCE PROGRAM OBJECT PROGRAM (which can be directly executed on computer)

4. 3.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

5. Figure 3.2 Compiling and Running a Procedural Language Program SOURCE PROGRAM OBJECT PROGRAM

6. Figure 3.3 Interpreting and Running an Interpretive Language Program SOURCE PROGRAM

7. 4.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

8. 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

9. 1.Applications software 2.Support software K EY T YPES OF S OFTWARE Figure 3.4 The Software Iceberg

10. Spheres of Influence & Application Software Personal Workgroup Enterprise programs that serve the needs of an individual user word processing, spreadsheets, databases, e-mail 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

11. 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 A PPLICATIONS S OFTWARE

12. 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 A PPLICATIONS S OFTWARE Examples of Applications Packages

13. Figure 3.5 “My Business Page” from Peachtree Complete Accounting

14. Word processing Spreadsheets Presentation graphics Electronic mail and groupware Database management systems Desktop publishing Web browsers Statistical packages A PPLICATIONS S OFTWARE Personal Productivity Software

15. 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 A PPLICATIONS S OFTWARE Personal Productivity Software

16. Spreadsheets  Used to create applications that fit a row-column format  Most popular is Microsoft Excel  Others are Lotus 1-2-3 and Corel Quattro Pro  All employ rows, columns, cells, formulas, “what-if” analysis A PPLICATIONS S OFTWARE Personal Productivity Software

18. 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 A PPLICATIONS S OFTWARE Personal Productivity Software

19. 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 A PPLICATIONS S OFTWARE Personal Productivity Software

20. 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 e-mail) A PPLICATIONS S OFTWARE Personal Productivity Software

21. Electronic Mail  Preferred way of communicating in business today  Easy to use and precise Groupware  Incorporates e-mail and other productivity features, such as calendaring, scheduling, and document sharing A PPLICATIONS S OFTWARE Personal Productivity Software

22. 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 A PPLICATIONS S OFTWARE Personal Productivity Software

23. A PPLICATIONS S OFTWARE Personal Productivity Software Microsoft Office 2003 EditionApplicationsPurposeRetail price Standard Word Excel PowerPoint Outlook Word processing Spreadsheets Presentation graphics E-mail, scheduling $399 Small Business Adds: Publisher Desktop publishing $449 Professional Adds: Access Database management $499

24. User communicates with operating system software to control hardware and software resources Communication made easier with a graphical user interface (GUI) feature S UPPORT S OFTWARE The Operating System Operating system – complex program that controls operation of computer hardware and coordinates other software

25. S UPPORT S OFTWARE The Operating System Job Control Language (JCL) – keyed instructions from the computer user to communicate with the operating system

26. 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

27. 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 S UPPORT S OFTWARE The Operating System

28. S UPPORT S OFTWARE The Operating System Multiprocessing – work that takes place when two or more CPUs are installed on same computer system

29. Sources of Operating Systems  Microcomputers: Windows XP; Windows Vista; Mac OS X  Midrange systems: OS/400  Large systems: VM and MVS S UPPORT S OFTWARE The Operating System Proprietary systems – most popular type of operating systems, written for a particular computer hardware configuration

30. Sources of Operating Systems  Examples: UNIX and Linux 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

31. Sources of Operating Systems  Enhanced operating system to allow for sharing disk drives and printers handling server side of client/server applications 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

32. Sources of Operating Systems Major players include: UNIX and Linux Microsoft Windows NT, 2000 Server, 2003 Server Novell NetWare 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

33. Procedural languages (3GL)  Require logical thinking  Entail development of a detailed step-by- step procedure  Can be developed using structured programming S UPPORT S OFTWARE Third Generation Languages

34. Advantages:  Program logic easier to follow  Maintenance and correction easier and faster  Do not use GO TO logic S UPPORT S OFTWARE Third Generation Languages Structured programs – divided into modules, where each has one entry and one exit point

35. S UPPORT S OFTWARE Third Generation Languages Table 3.1 Stages in the Program Development Process

36. Most popular procedural languages:  BASIC  C  COBOL S UPPORT S OFTWARE Third Generation Languages

37. Figure 3.9 BASIC Program

38. Figure 3.10 C Program

39. Figure 3.11 COBOL Program

42. Other procedural languages:  FORTRAN  PL/1  PASCAL  ADA S UPPORT S OFTWARE Third Generation Languages

43. Nonprocedural languages:  Use very high-level instructions  Require fewer instructions  Easier to write, modify, understand  Example: FOCUS S UPPORT S OFTWARE Fourth Generation Languages

44. Figure 3.12 FOCUS Program and Output

45. Most popular:  HTML: used to create Web pages  XML: used to facilitate data interchange among Web applications S UPPORT S OFTWARE Markup Languages

46. 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 S UPPORT S OFTWARE Object-Oriented Programming

47. Figure 3.13A Visual Basic Program

48. Figure 3.13B Visual Basic Screen Layout

49. HTML XML Server-side programming languages:  Perl  Java Servlets and Java Server Pages  Microsoft Active Server Pages (ASP, ASP.NET)  ColdFusion S UPPORT S OFTWARE Languages for Developing Web Applications

50. Figure 3.17 Grocery Store HTML Form

51. Figure 3.17 HTML and ASP.NET code to accompany Grocery Store HTML Form

52. Figure 3.18 Program to Process Data from Grocery Store HTML Form

53. Figure 3.19 Grocery Store Confirmation Web Page

54. Figure 3.19 Code to Generate Confirmation Web Page

55. 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 S UPPORT S OFTWARE Database Management Systems

56. 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 S UPPORT S OFTWARE File Organization Figure 3.20 File Organizations

57. 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 File Organization Figure 3.20 File Organizations

58. Figure 3.21 Relationship Schemes Relational DBMSs use this scheme

59.  Growth slower than anticipated  Radically changed nature of systems analyst and programmer jobs 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

60. 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) S UPPORT S OFTWARE Communications Interface Software

61. 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 T HE C HANGING N ATURE OF S OFTWARE

62. 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

63. 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

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

65. Customer self-service software on the Internet from FedEx was an example of first-mover advantages