Chapter 11 Information System Development and Programming Languages

1
Chapter 11 Information System Development and
Programming Languages
2
Chapter 11 Objectives
Discuss the importance of project management,
feasibility assessment, documentation, data and
information gathering techniques, and information
systems security during system development
List other programming languages and other
program development tools
Describe various ways to develop Web pages
Discuss the purpose of each phase in the system
development cycle
List the six steps in the program development
cycle
Differentiate between low-level languages and
procedural languages
Explain the basic control structures used in
designing solutions to programming problems
Identify the benefits of object-oriented and
visual programming languages
3
The System Development Life Cycle

• What is an information system (IS)?

Hardware, software, data, people, and procedures
that work together to produce quality information
SystemSet of components that interact to achieve
common goal
Businesses use many types of systems
p. 406
4
The System Development Life Cycle

• What are the phases of the system development
  cycle?

Phase 2. Analysis

• Conduct preliminary investigation
• Perform detailed analysis activities
• Study current system
• Determine user requirements
• Recommend solution

Phase 1. Planning
Phase 3. Design

• Review project requests
• Prioritize project requests
• Allocate resources
• Identify project development team

• Acquire hardware and software, if necessary
• Develop details of system

Phase 4. Implementation
Phase 5. Support

• Develop programs, if necessary
• Install and test new system
• Train users
• Convert to new system

• Conduct post-implementation system review
• Identify errors and enhancements
• Monitor system performance

p. 406 Fig. 11-1
5
The System Development Life Cycle

• What are guidelines for system development?

Arrange tasks into phases (groups of activities)

• Involve users (anyone for whom system is being
  built)

Develop clearly defined standards (procedures
company expects employees to follow)
p. 406 - 407
6
The System Development Life Cycle

• Who participates in the system development life
  cycle?

p. 407 Fig. 11-2
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The System Development Life Cycle

• What is a systems analyst?

Responsible for designing and developing
information system
Liaison between users and IT professionals
p. 407
8
The System Development Life Cycle

• What is the project team?

Formed to work on project from beginning to end
Consists of users, systems analyst, and other IT
professionals
Project leaderone member of the team who
manages and controls project budget and schedule
p. 408
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The System Development Life Cycle

• What is project management?

• Process of planning, scheduling, and controlling
  activities during system development cycle
• Project leader identifies elements for project

Required activities
Goal, objectives, and expectations, collectively
called scope
Time estimates for each activity
Cost estimates for each activity
Activities that can take place at same time
Order of activities
p. 408
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The System Development Life Cycle

• What is a Gantt chart?

• Popular tool used to plan and schedule time
  relationships among project activities

p. 409 Fig. 11-3
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The System Development Life Cycle

• What is feasibility?

Operational feasibility
Measure of how suitable system development will
be to the company
Four feasibility tests
Schedule feasibility
Economic feasibility (also called cost/benefit
feasibility)
Technical feasibility
p. 409
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The System Development Life Cycle

• What is documentation?

Collection and summarization of data and
information
Includes reports, diagrams, programs, and other
deliverables
p. 409
13
The System Development Life Cycle

• What are six data and information gathering
  techniques?

• Review documentation
• Observe
• Questionnaire
• Interview
• Joint-application design (JAD) session
• Research

p. 410 Fig. 11-4
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The System Development Life Cycle

• What are some reasons to create or modify an
  information system?

To improve existing system
To correct problem in existing system
Competition can lead to change
Outside group may mandate change
p. 410
15
The System Development Life Cycle

• What is a request for system services?

• Formal request for new or modified information
  system
• Also called project request

p. 411 Fig. 11-5
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The System Development Life Cycle

• What is the planning phase?

Begins when steering committee receives project
request
Steering committeedecision-making body for the
company
Function of committee
Review and approve project requests
Allocate resources
Form project development team for each approved
project
Prioritize project requests
p. 412
17
The System Development Life Cycle

• What is the analysis phase?

p. 413
18
The System Development Life Cycle

• What is the preliminary investigation?

• Determine exact nature of problem or improvement
  and whether it is worth pursuing

• Findings are presented in feasibility report,
  also known as a feasibility study

p. 413 - 414 Fig. 11-6
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The System Development Life Cycle

• What is detailed analysis?

1. Study how current system works
2. Determine users wants, needs, and requirements
3. Recommend solution
Sometimes called logical design
p. 415
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The System Development Life Cycle

• What is the system proposal?

p. 415
21
The System Development Life Cycle

• What are possible solutions?

Horizontal market softwaremeets needs of many
companies
Buy packaged softwareprewritten software
available for purchase
Vertical market softwaredesigned for particular
industry
Write own custom softwaresoftware developed at
users request
Outsourcehave outside source develop software
p. 415
22
The System Development Life Cycle

• What is the design phase?

Acquire hardware and software
Develop all details of new or modified
information system
p. 416
23
The System Development Life Cycle

• What is needed to acquire new hardware and
  software?

• Identify all hardware and software requirements
  of new or modified system

Surf Web
Talk with other systems analysts
Visit vendors stores
Read print and online trade journals, newspapers,
and magazines

• E-zine, or electronic magazine, is publication
  available on Web

p. 416
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The System Development Life Cycle

• What are three basic documents used to summarize
  technical specifications?

Request for quotation (RFQ)
Request for proposal (RFP)
Request for information (RFI)
p. 416
25
The System Development Life Cycle

• What is a value-added reseller (VAR)?

• Complete system provided by value-added reseller

• Value-added reseller (VAR) purchases products
  from manufacturer and then resells them, offering
  additional services with product
• Authorized VARs must meet certain
  manufacturer-specified requirements

p. 417 Fig. 11-7
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The System Development Life Cycle

• How do systems analysts test software products?

• References from vendor
• Talk to current users of product
• Product demonstrations
• Trial version of software
• Benchmark test measures performance

p. 417
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The System Development Life Cycle

• What is a detailed design?

Detailed design specifications for components in
proposed solution
Includes several activities
Database design
Input and output design
Program design
p. 418 - 419
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The System Development Life Cycle

• What is a mockup?

• Sample of input or output that contains actual
  data

p. 418 Fig. 11-8
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The System Development Life Cycle

• What is a layout chart?

• Input or output that contains programming-like
  notations for data items

p. 419 Fig. 11-9
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The System Development Life Cycle

• What is a prototype?

Working model of proposed system
Beginning a prototype too early may lead to
problems
p. 419
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The System Development Life Cycle

• What is computer-aided software engineering
  (CASE)?

• Software tools designed to support activities of
  system development cycle

p. 419 Fig. 11-10
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The System Development Life Cycle

• What is the implementation phase?

• Purpose is to construct, or build, new or
  modified system and then deliver it to users

Convert to new system
Train users
Install and test new system
Develop programs
p. 420
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The System Development Life Cycle

• What are the three types of tests performed by
  system developers?

Systems test
Unit Test
Verifies each individual program works by itself
Verifies all programs in application work together
Integration Test
Acceptance Test
Verifies application works with other applications
Verifies the new system works with actual data
p. 420
34
The System Development Life Cycle

• What is training?

• Showing users exactly how they will use new
  hardware and software in system

p. 421 Fig. 11-11
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The System Development Life Cycle

• What are conversion strategies?

• Used to change from old system to new system

p. 421
36
The System Development Life Cycle

• Conduct post-implementation system reviewmeeting
  to find out if information system is performing
  according to expectations

Identify errors

• What is the support phase?

• Provides ongoing assistance after system is
  implemented

Identify enhancements
Monitor system performance
p. 422
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Information System Security

• What is a computer security plan?

• Summarizes in writing all of the safeguards that
  are in place to protect a companys information
  assets

For each risk,identify thesafeguards that
exist to detect, prevent, and recover from a
loss
Identify allsecurity risksthat may cause an
informationloss
Identify allinformation assets of an
organization
p. 422
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Programming Languages

• What is a computer program?

• Set of instructions that directs computer to
  perform tasks

• Programming languageused to write instructions

p. 423 Fig. 11-12
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Programming Languages

• What are low-level languages and high-level
  languages?

High-level language
Low-levellanguage
Machine-dependentruns only on one type of
computer
Often machine-independentcan run on many
different types of computers
Machine and assembly languages are low-level
p. 424
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Programming Languages

• What is machine language?

• Only language computer directly recognizes
• Uses a series of binary digits (1s and 0s) with a
  combination of numbers and letters that represent
  binary digits

p. 424 Fig. 11-13
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Programming Languages

• What is assembly language?

• Instructions made up of symbolic instruction
  codes, meaningful abbreviations and codes
• Source program contains code to be converted to
  machine language

p. 424 Fig. 11-14
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Programming Languages

• What is a procedural language?

Uses series of English-like words to write
instructions
Programmer writes instructions that tell computer
what to accomplish and how to do it
Most widely used are BASIC, COBOL, and C
Often called third-generation language (3GL)
p. 425
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Programming Languages

• What is a compiler?

• Program that converts entire source program into
  machine language before executing it

p. 425 Fig. 11-15
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Programming Languages

• What is an interpreter?

• Program that translates and executes one program
  code statement at a time

• Does not produce object program

p. 426 Fig. 11-16
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Programming Languages

• What is COBOL?

• Designed for business applications
• English-like statements make code easy to read,
  write, and maintain
• COmmon Business-Oriented Language

p. 426 Fig. 11-17
46
Programming Languages

• What is C?

• Powerful language originally designed to write
  system software
• Requires professional programming skills

p. 427 Fig. 11-18
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Programming Languages

• What is an object-oriented programming (OOP)
  language?

Used to implement object-oriented design
Major benefit is ability to reuse existing
objects

• Event-drivenchecks for and responds to set of
  events

C and Java are complete object-oriented
languages
Object is item that contains data and
procedures that act on data
Event is action to which program responds
p. 427
48
Programming Languages

• What is Java?

• Developed by Sun Microsystems
• Similar to C but uses just-in-time (JIT)
  compiler to convert source code into machine code

p. 427 Fig. 11-19
49
Programming Languages

• What is C?

• Includes all elements of C, plus additional
  features for working with object-oriented
  concepts
• Used to develop database and Web applications

What is C?

• Object-oriented programming language based on C
• Accepted as a standard for Web applications and
  XML-based Web services

p. 428
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Programming Languages

• What is a visual programming language?

Provides visual or graphical interface for
creating source code
Sometimes calledfifth-generation language
Often used in RAD (rapid application development)
environment
p. 428
51
Programming Languages

• What is Visual Studio 2005?

• .NET is set of technologies that allows program
  to run on Internet
• Comprised of Visual Basic 2005, Visual C 2005,
  Visual C 2005, and Visual J 2005

p. 428 Fig. 11-20
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Programming Languages

• What is Delphi?

• Powerful visual programming tool
• Ideal for large-scale enterprise and Web
  applications

What is PowerBuilder?

• Another powerful visual programming tool
• Best suited for Web-based and large-scale
  object-oriented applications

p. 429
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Programming Languages

• What is RPG (Report Program Generator)?

• Used for generating reports, performing
  computations, and updating files

p. 430 Fig. 11-21
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Programming Languages

• What is a fourth-generation language (4GL)?

• Nonprocedural language that allows access to data
  in database
• Popular 4GL is SQL, query language that allows
  users to manage data in relational DBMS

p. 430 Fig. 11-22
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Programming Languages

• What are other available programming languages?

ALGOL
ADA
APL
FORTH
LISP
HYPERTALK
FORTRAN
LOGO
PASCAL
MODULA-2
PILOT
SMALLTALK
PROLOG
PL/I
p. 431
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Programming Languages

• What is an application generator?

• Program that creates source code or machine code
  from specification
• Consists of report writer, form, and menu
  generator

• Form provides areas for entering data

p. 431 - 432 Fig. 11-24
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Programming Languages

• What is HTML (Hypertext Markup Language)?

• Used to create Web pages

p. 433 Fig. 11-25
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Programming Languages

• What is a scripting language?

• Typically easy to learn and use

• JavaScriptadds dynamic content and interactive
  elements to Web page
• VBScript (Visual Basic, Scripting Edition)adds
  intelligence and interactivity to Web page
• Perl (Practical Extraction and Report
  Language)has powerful text processing
  capabilities

p. 434 - 435 Fig. 11-26
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Programming Languages

• What is dynamic HTML (DHTML)?

• Allows developers to include more graphical
  interest and interactivity in Web page

p. 435 Fig. 11-27
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Programming Languages

• What are XHTML, XML, and WML?

Includes features of HTML and XML
XHTML (Extensible HTML)enables Web sites to be
displayed more easily on microbrowsers
XML (Extensible Markup Language)allows
developers to create customized tags
Server sends entire record to client, enabling
client to do much of processing without going
back to server
WML (Wireless Markup Language)allows developers
to design pages specifically for microbrowsers
Many PDAs and smart phones use WML as their
markup language
p. 436
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Programming Languages

• What is Web page authoring software?

• Creates sophisticated Web pages without using
  HTML
• Generates HTML

p. 436
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Programming Languages

• What is multimedia authoring software?

• Combines text, graphics, animation, audio, and
  video into interactive presentation
• Used for computer-based training (CBT) and
  Web-based training (WBT)

• Software includes Toolbook, Authorware, and
  Director MX

p. 437 Fig. 11-28
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The Program Development Cycle

• What is the program development cycle?

• Steps programmers use to build computer programs

• Programming teamGroup of programmers working on
  program

p. 438 Fig. 11-29
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The Program Development Cycle

• What is a sequence control structure?

• Control structure that shows actions following
  each other in order

• Control structure depicts logical order of
  program instructions

p. 440 Fig. 11-30
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The Program Development Cycle

• What is a selection control structure?

• Tells program which action to take, based on a
  certain condition
• Two types

• Case control structure
• If-then-else control structureyields one of two
  possibilities true or false

p. 440 Fig. 11-31
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The Program Development Cycle

• What is a case control structure?

• Yields one of three or more possibilities

p. 440 - 441 Fig. 11-32
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The Program Development Cycle

• What is a repetition control structure?

• Enables program to perform one or more actions
  repeatedly

• Do-while control structurerepeats as long as
  condition is true

• Do-until control structurerepeats until
  condition is true

p. 441 Figs. 11-3311-34
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Summary of Information System Development and
Programming Languages
Phases in the system development life cycle
Various programming languages and program
development tools used to write and develop
computer programs
Web development and multimedia development tools
Guidelines for system development
Program development cycle
Activities that occur during the entire system
development cycle
Chapter 11 Complete