Transcript Slide 1
MANAGING INFORMATION TECHNOLOGY
FIFTH EDITION
CHAPTER 3
C
OMPUTER
S
OFTWARE
E. Wainright Martin Carol V. Brown Daniel W. DeHayes Jeffrey A. Hoffer William C. Perkins
E
VOLUTION OF
C
OMPUTER
P
ROGRAMMING
First and Second Generation Languages
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 © 2005 Pearson Prentice-Hall Chapter 3 - 2
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E
VOLUTION OF
C
OMPUTER
P
ROGRAMMING
First and Second Generation Languages SOURCE PROGRAM OBJECT PROGRAM (which can be directly executed on computer)
© 2005 Pearson Prentice-Hall Chapter 3 - 3
Figure 3.1 Assembler Translation Process Page 53
E
VOLUTION OF
C
OMPUTER
P
ROGRAMMING
Third and Fourth Generation Languages
3.
Procedural Languages (3GL)
Generally are machine independent.
Express a step-by-step procedure developed by programmer Must be compiled or interpreted machine language) (translated into Include FORTRAN, COBOL, BASIC, PL/1, PASCAL, ADA, and C © 2005 Pearson Prentice-Hall Chapter 3 - 4
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SOURCE PROGRAM OBJECT PROGRAM
© 2005 Pearson Prentice-Hall Chapter 3 - 5
Figure 3.2 Compiling and Running a Procedural Language Program Page 54
SOURCE PROGRAM © 2005 Pearson Prentice-Hall Chapter 3 - 6
Figure 3.3 Interpreting and Running an Interpretive Language Program Page 54
E
VOLUTION OF
C
OMPUTER
P
ROGRAMMING
Third and Fourth Generation Languages
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 © 2005 Pearson Prentice-Hall Chapter 3 - 7
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E
VOLUTION OF
C
OMPUTER
P
ROGRAMMING
Third and Fourth Generation Languages
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 © 2005 Pearson Prentice-Hall Chapter 3 - 8
Figure 3.4 The Software Iceberg Page 55
K
EY
T
YPES OF
S
OFTWARE
1.
2.
Applications software Support software © 2005 Pearson Prentice-Hall Chapter 3 - 9
Figure 3.4 The Software Iceberg Page 56
Spheres of Influence & Application Software
• Two or more people who work together to achieve a common goal • Systems that support information sharing, group scheduling, group decision making, and conferencing
Personal Workgroup Enterprise
• programs that serve the needs of an individual user • word processing, spreadsheets, databases, e-mail © 2005 Pearson Prentice-Hall Chapter 3 - 10 • programs that support the firm in its interaction with its environment • order entry, billing
A
PPLICATIONS
S
OFTWARE
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 © 2005 Pearson Prentice-Hall Chapter 3 - 11
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A
PPLICATIONS
S
OFTWARE
Examples of Applications Packages
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 © 2005 Pearson Prentice-Hall Chapter 3 - 12
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© 2005 Pearson Prentice-Hall Chapter 3 - 13
Figure 3.5 “My Business Page” from Peachtree Complete Accounting Page 58
A
PPLICATIONS
S
OFTWARE
Personal Productivity Software
Word processing Spreadsheets Presentation graphics Electronic mail and groupware Database management systems Desktop publishing Web browsers Statistical packages © 2005 Pearson Prentice-Hall Chapter 3 - 14
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A
PPLICATIONS
S
OFTWARE
Personal Productivity Software
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 © 2005 Pearson Prentice-Hall Chapter 3 - 15
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A
PPLICATIONS
S
OFTWARE
Personal Productivity Software
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 © 2005 Pearson Prentice-Hall Chapter 3 - 16
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© 2005 Pearson Prentice-Hall Chapter 3 - 17
Figure 3.6 Microsoft Excel Spreadsheet Page 61
A
PPLICATIONS
S
OFTWARE
Personal Productivity Software
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 © 2005 Pearson Prentice-Hall Chapter 3 - 18
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A
PPLICATIONS
S
OFTWARE
Personal Productivity Software
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 © 2005 Pearson Prentice-Hall Chapter 3 - 19
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A
PPLICATIONS
S
OFTWARE
Personal Productivity Software
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) © 2005 Pearson Prentice-Hall Chapter 3 - 20
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A
PPLICATIONS
S
OFTWARE
Personal Productivity Software
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 © 2005 Pearson Prentice-Hall Chapter 3 - 21
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A
PPLICATIONS
S
OFTWARE
Personal Productivity Software
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 © 2005 Pearson Prentice-Hall Chapter 3 - 22
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A
PPLICATIONS
S
OFTWARE
Personal Productivity Software
Edition
Standard Small Business Professional
Microsoft Office 2003
Applications Purpose
Word Excel PowerPoint Outlook
Adds:
Publisher Word processing Spreadsheets Presentation graphics E-mail, scheduling Desktop publishing
Adds:
Access Database management
Retail price
$399 $449 $499 © 2005 Pearson Prentice-Hall Chapter 3 - 23
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S
UPPORT
S
OFTWARE
The Operating System Operating system
– complex program that controls operation of computer hardware and coordinates other software User communicates with operating system software to control hardware and software resources Communication made easier with a graphical user interface (GUI) feature © 2005 Pearson Prentice-Hall Chapter 3 - 24
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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 3 - 25
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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 3 - 26
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S
UPPORT
S
OFTWARE
The Operating System
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 © 2005 Pearson Prentice-Hall Chapter 3 - 27
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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 3 - 28
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S
UPPORT
S
OFTWARE
The Operating System
Sources of Operating Systems
Proprietary systems
– most popular type of operating systems, written for a particular computer hardware configuration Microcomputers: MS-DOS, PC-DOS, Windows XP Midrange systems: OS/400 Large systems: VM and MVS © 2005 Pearson Prentice-Hall Chapter 3 - 29
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S
UPPORT
S
OFTWARE
The Operating System
Sources of Operating Systems
Open systems
– not tied to any particular computer system or hardware manufacturer – will run on virtually any computer system Examples: UNIX and Linux © 2005 Pearson Prentice-Hall Chapter 3 - 30
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S
UPPORT
S
OFTWARE
The Operating System
Sources of Operating Systems
Network operating systems (NOS)
– software running on a server that manages network resources and controls the operation of a network Enhanced operating system to allow for sharing disk drives and printers handling server side of client/server applications © 2005 Pearson Prentice-Hall Chapter 3 - 31
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S
UPPORT
S
OFTWARE
The Operating System
Sources of Operating Systems
Network operating systems (NOS)
– software running on a server that manages network resources and controls the operation of a network
Major players include:
UNIX and Linux Microsoft Windows NT, 2000 Server, 2003 Server Novell NetWare © 2005 Pearson Prentice-Hall Chapter 3 - 32
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S
UPPORT
S
OFTWARE
Third Generation Languages
Procedural languages (3GL)
Require logical thinking Entail development of a detailed step-by step procedure Can be developed using structured programming © 2005 Pearson Prentice-Hall Chapter 3 - 33
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S
UPPORT
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OFTWARE
Third Generation Languages Structured programs
– divided into modules, where each has one entry and one exit point
Advantages:
Program logic easier to follow Maintenance and correction easier and faster Do not use GO TO logic © 2005 Pearson Prentice-Hall Chapter 3 - 34
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S
UPPORT
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OFTWARE
Third Generation Languages
© 2005 Pearson Prentice-Hall Chapter 3 - 35
Table 3.1 Stages in the Program Development Process Page 70
S
UPPORT
S
OFTWARE
Third Generation Languages
Most popular procedural languages:
BASIC C COBOL © 2005 Pearson Prentice-Hall Chapter 3 - 36
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© 2005 Pearson Prentice-Hall Chapter 3 - 37
Figure 3.9 BASIC Program Page 71
© 2005 Pearson Prentice-Hall Chapter 3 - 38
Figure 3.10 C Program Page 72
© 2005 Pearson Prentice-Hall Chapter 3 - 39
Figure 3.11 COBOL Program Page 73
© 2005 Pearson Prentice-Hall Chapter 3 - 40
Figure 3.11 COBOL Program Page 73
© 2005 Pearson Prentice-Hall Chapter 3 - 41
Figure 3.11 COBOL Program Page 74
S
UPPORT
S
OFTWARE
Third Generation Languages
Other procedural languages:
FORTRAN PL/1 PASCAL ADA © 2005 Pearson Prentice-Hall Chapter 3 - 42
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S
UPPORT
S
OFTWARE
Fourth Generation Languages
Nonprocedural languages:
Use very high-level instructions Require fewer instructions Easier to write, modify, understand Example:
FOCUS
© 2005 Pearson Prentice-Hall Chapter 3 - 43
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© 2005 Pearson Prentice-Hall Chapter 3 - 44
Figure 3.12 FOCUS Program and Output Page 76
S
UPPORT
S
OFTWARE
Markup Languages
Most popular: HTML
: used to create Web pages
XML
: used to facilitate data interchange among Web applications © 2005 Pearson Prentice-Hall Chapter 3 - 45
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S
UPPORT
S
OFTWARE
Object-Oriented Programming
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
© 2005 Pearson Prentice-Hall Chapter 3 - 46
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© 2005 Pearson Prentice-Hall Chapter 3 - 47
Figure 3.13A Visual Basic Program Page 80
© 2005 Pearson Prentice-Hall Chapter 3 - 48
Figure 3.13B Visual Basic Screen Layout Page 81
S
UPPORT
S
OFTWARE
Languages for Developing Web Applications
HTML Server-side programming languages: Perl Java Servlets and Java Server Pages Microsoft Active Server Pages (ASP, ASP.NET) ColdFusion © 2005 Pearson Prentice-Hall Chapter 3 - 49
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© 2005 Pearson Prentice-Hall Chapter 3 - 50
Figure 3.17 Grocery Store HTML Form Page 84
HTML and ASP.NET code to accompany Grocery Store HTML Form
© 2005 Pearson Prentice-Hall Chapter 3 - 51
Figure 3.17
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© 2005 Pearson Prentice-Hall Chapter 3 - 52
Figure 3.18
Program to Process Data from Grocery Store HTML Form Page 86
© 2005 Pearson Prentice-Hall Chapter 3 - 53
Figure 3.19 Grocery Store Confirmation Web Page Page 86
© 2005 Pearson Prentice-Hall Chapter 3 - 54
Figure 3.19
Code to Generate Confirmation Web Page Page 86
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UPPORT
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OFTWARE
Database Management Systems
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 © 2005 Pearson Prentice-Hall Chapter 3 - 55
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UPPORT
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OFTWARE
File Organization 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 © 2005 Pearson Prentice-Hall Chapter 3 - 56
Figure 3.20 File Organizations Page 88
S
UPPORT
S
OFTWARE
File Organization
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 © 2005 Pearson Prentice-Hall Chapter 3 - 57
Figure 3.20 File Organizations Page 88
Relational DBMSs use this scheme
© 2005 Pearson Prentice-Hall Chapter 3 - 58
Figure 3.21 Relationship Schemes Page 89
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UPPORT
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OFTWARE
CASE Tools Computer-aided software engineering (CASE)
– collection of software tools to help automate all phases of the software development life cycle Growth slower than anticipated Radically changed nature of systems analyst and programmer jobs © 2005 Pearson Prentice-Hall Chapter 3 - 59
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UPPORT
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OFTWARE
Communications Interface Software
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) © 2005 Pearson Prentice-Hall Chapter 3 - 60
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T
HE
C
HANGING
S
OFTWARE
N
ATURE OF
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 © 2005 Pearson Prentice-Hall Chapter 3 - 61
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T
HE
S
OFTWARE
C
OMPONENT OF THE
I
NFORMATION
S
YSTEMS
I
NDUSTRY
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 © 2005 Pearson Prentice-Hall Chapter 3 - 62
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Trends in Computer Software
Trend: Toward Easy-to-Use Multipurpose Network-Enabled Application Packages for Productivity and Collaboration 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 Visual or Conversational Programming Languages and Tools
© 2005 Pearson Prentice-Hall Chapter 3 - 63
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
”