Lecture Notes

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Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
CHAPTER 14
INFORMATION SYSTMES
DEVELOPMENT
2
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
Learning Objectives
 Discuss the concept of a systems development life cycle
(SDLC)
 Describe the information systems planning process
 Discuss the advantages and disadvantages of the
traditional development, prototyping, rapid application
development, object-oriented development, and end-user
development life cycles
 Identify the advantages and disadvantages of CASE tools
 Evaluate the alternatives to in-house systems development
 Discuss the key features of Internet and intranet
development
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
3
Chapter Overview
Information Systems
Planning
• The IS Strategic Plan
• The IS Operational
Plan
The Traditional SDLC Alternative Methods for
Systems Development
• System Investigation • Prototyping
• Systems Analysis
• Join Application Design (JAD)
• Systems Design
• Rapid Application
• Programming
Development (RAD)
• Testing
• Integrated Computer-Assisted
• Implementation
Software Engineering (ICASE)
• Operation and
Tools
Maintenance
• Object-Oriented Development
Systems Development
Outside the IS Department
• End-User development
• External Acquisition of
Software
• Outsourcing
Building Internet and
Intranet Applications
• An Internet and Intranet
Development Strategy
• Java - A Promising Tool
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
4
Case: Success in Systems Development
at Inland Steel is a Team Effort
 The Business Problem
 How to complete Inland Steel’s Order
Fulfillment System (OFS), a huge systems
development project, successfully on time and on budget
The Solution
 reviewed all requests from the business units for changes and
enhancements, and approved only a dozen, to minimize the
tendency of a project’s goals to grow beyond initial
specifications during the development process
The Results
 reduce by 50 percent the response time to customer inquiries
 upgraded and expanded some jobs from clerical to
professional functions
 integrating information in an IBM DB2 relational database
that previously had resided in isolated databases
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Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
Case (continued…)
What have we learned from this case??
 Information system’s timely and careful
development is a very high priority
 Many firms no longer attempt a major
systems development by themselves
 System development is a team effort that often
includes end users, top management, IS
professional, vendors, consultants, and
whatever other specialized expertise is
necessary
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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Information Systems Planning
Organization
Mission
Business
Assessment
Organization
Strategic Plan
IS Planning Process
Current Information
Technology Architecture
IS Strategic Plan
New information Technology Architecture
IS Operational Plan
IS Development Projects
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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IS Planning (continued …)
The IS Strategic Plan
 Objectives
 it must be aligned with the organization’s strategic plan
 it must provide for an IT architecture that enables
users, applications, and databases to be seamlessly
networked and integrated
 it must efficiently allocate IS development resources
among competing projects, so the projects can be
completed on time, within budget, and have required
the functionality
 Issues : efficiency; effectiveness; competitiveness
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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IS Planning (continued …)
The IS Operational Plan
 Mission : the mission of the IS function
 IS environment : the summary of the information needs




of the functional areas and of the organization as a whole
Objectives of the IS function : the IS function’s current
best estimate of its goals
Constraints on the IS function : technological, financial,
and personnel limitations on the IS function
Long-term systems need : a summary of the processes
needed by a company and the IS projects selected to
support them and reach organizational goals
Short-range plan : an inventory of current projects, and a
detailed plan of projects to be developed or continued
during the current year
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Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
The Traditional Systems
Development Life Cycle (SDLC)
 SDLC - the development method used by most
organizations today for large, complex systems
 Waterfall Approach - a sequence of steps in the SDLC
with cycles returned to previous stops
 Systems Analysts - IS professionals who specialize in
analyzing and designing information systems
 Programmers - IS professionals who modify existing
computer programs or write new computer programs to
satisfy user requirements
 Technical Specialists - experts in a certain type of
technology, such as databases or telecommunications
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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SDLC (continued …)
An eight-stage systems
development life cycle
(SDLC)
(1) Systems Investigation
(2) Systems Analysis
(3) Systems Design
(4) Programming
(5) Testing
(6) Implementation
(7) Operation
(8) Maintenance
Go Back to a previous Stage or Stop
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Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
SDLC (continued …)
Systems Investigation (Step 1)
 Feasibility Study determines the probability of
success of proposed system’s development project
and assesses the project’s
 technical feasibility : determines if the hardware,
software, and communication components can be
developed or acquired to solve the business problem
 economic feasibility : determines if the project is an
acceptable financial risk and if the organization can
afford the expense and time needed to complete the
project
 behavioral feasibility : addresses the human issues of the
project
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Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
SDLC (continued …)
Systems Analysis (Step 2)
 the examination of the business problem
that the organization plans to solve with
information systems
 produces the following information
 strengths and weaknesses of the
existing system
 functions that the new systems must
have to solve the business problem
 user information requirements for the
new systems
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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SDLC (continued …)
Systems Design (Step 3)
 describes how the system will accomplish the task
 technical design
 system outputs, inputs, and user interfaces
 hardware, software, databases, telecommunications,
personnel, and procedures
 how these components are integrated
 local systems design : what the system will do
 Physical systems design : how the system will
perform its functions
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Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
SDLC (continued …)
Programming (Step 4)
 the translation of the design specifications
into computer code
 structured programming techniques :
improve the logical flow of the program by
decomposing the computer code into
modules, which are sections of code
 sequence structure
 decision structure
 loop structure
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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SDLC (continued …)
Testing (Step 5)
 checks to see if the computer code will
produce the expected and desired results
under certain conditions
 syntax errors : misspelled word or a
misplaced comma
 logic errors : permit the program to run,
but result in incorrect output
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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SDLC (continued …)
Implementation (Step 6)
 the process of converting from the old system to the
new system
 four major conversion strategies
 parallel conversion : the old and new systems
operate simultaneously for a period of time
 direct conversion : the old system is cut off and the
new systems is turned on at a certain point in time
 pilot conversion : introduces the new system in one
part of the organization
 phased conversion : introduces components of the
new systems in stages
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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SDLC (continued …)
Operation (Step 7)
 the new systems will operate for a period
of time, until it no longer meets its
objectives
Maintenance (Step 8)
 debugging the program
 updating the system to accommodate
changes in business conditions
 add new functionality to the system
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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Prototyping
Prototyping obtain only a general idea of user
requirements
 Advantages:
speeds up the development approach
gives the users the opportunity to clarify their
information requirements
useful in the development of decision support systems
and executive information systems
 Disadvantages:
 replaces the systematic analysis and design stages of
the SDLC - quality may be sacrificed
 can result in an excess of iterations
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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Joint Application Design (JAD)
JAD is a group-based method for collecting user
requirements and creating staged designs
 Advantages:
saves time
greater support for, and acceptance of new systems
produces higher quality systems
easier implementation
lower training costs
 Disadvantages:
 very difficult to get all users to JASD meetings
 all the problems that may be caused by any group process
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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Rapid Application Development
(RAD)
 RAD is a systems development method that can
combine JAD, prototyping, and integrated CASE
tools, to rapidly produce a high-quality system
 Advantages:
active involvement of users in the development process
speeds the development process
reduces development costs
can create applications that are easier to maintain and
modify
 Disadvantages:
 may result in systems with limited functionality and
adaptability for change
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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Integrated Computer-Assisted Software
Engineering (ICASE) Tools
 ICASE Tools automate many of the tasks in the SDLC
 Upper CASE, lower CASE and integrated CASE
 Advantages:
produces systems with a longer effective operational life
speeds up the development process and result in systems that
are more flexible and adaptable to changing business conditions
results in excellent documentation
 Disadvantages:
 more expensive to build and maintain initial system
 requires more extensive and accurate definition of user needs
and requirements
 difficult to customize and may be difficult to use with existing
system
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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Object-Oriented Development
 Object-Oriented Development based on a fundamentally
different view of computer systems than that found in traditional
SDLC development approaches
 Advantages:
reduces the complexity of systems development and leads to systems
that are easier and quicker to build an maintain
improves programmers’ productivity and quality
more flexible
allows systems analysts to think the real-world systems
ideal for developing Web applications
depicts the various elements of an information systems in user
standing of what the new system does and how it meets its objectives
 Disadvantages
 runs more slowly
 needs to retain the programmers
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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Systems Development outside
the IS Department
End-User Development
 users will continue to do more ad hoc programming
 Types of end-user computing:
 non programming end users : enter data, use
applications
 command-level users : access data, print reports
 end-user programmers : develop applications for
personal use
 functional support personnel : develop applications
for others to use
 end-user computing support personnel : training,
hotline, help users develop applications
 programmers : develop complex applications
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Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
Systems Development outside
the IS Department (continues …)
End-User Development (CONT’)
 Factors that drive the trends toward increased
end-user computing and end-user development
 increasingly powerful desktop hardware
 declining hardware costs
 increase diverse software capabilities
 increasingly computer literate population
 backlog of IS projects
 development speed
 business orientation
 small applications
 control
 Apparent cost savings  User friendly software
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Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
Systems Development outside
the IS Department (continues …)
 Advantages of End-User Development
 gives users control over both the initial development of
an application and the ongoing maintenance
 no need to explain user requirements to IS analysts
 gives users control over the development budget
 results in the possibility of greater user acceptance
 Disadvantages of End-User Development
 needs some additional spending
 difficult for managers outside the IS area to evaluate
end-user development activities
 fail to produce adequate documentation for the systems
 security may be breached
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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Systems Development outside
the IS Department (continues …)
External Acquisition of Software
 factors considered during make-or-buy
decision










on-time
on-budget
full functionality
user acceptance
favorable costs-to-benefits ratio
low maintenance
scalability
integration with other systems
minimal negative cross-impacts
reusability
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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Systems Development outside
the IS Department (continues …)
Outsourcing
 purchase of any product or service from other company
 advantages:
 Disadvantages:
economies of scale of
hardware
economies of scale of
staffing
specialization
tax benefits
 guidelines:
 limited economies of scale
 staffing
 lack of business expertise
 contract problems
 internal cost reduction
opportunities
 write short-period contracts
 subcontracting
 selective outsourcing
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Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
Building Internet and
Intranet Applications
An Internet and intranet
Development Strategy
 identify the objectives for
organizational Web site(s) and pages
 adequately cover infrastructure
requirements as well as security are
legal issues
 identify and prioritize potential projects
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Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
Internet and Intranet
JAVA - A Promising Tools
 the most important programming language for
putting extra features into Web pages
 an object-oriented language
 can be sent from a Web server over the Internet
and then run on the computer that is viewing the
Web page
 has numerous security features to prevent
downloaded programs from damaging files or
creating other problems on the receiving computer
Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
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What’s in IT for Me?
For Accounting
 accounting functions are traditionally data-intensive
 properly developed systems are a must
For Finance
 those acquainted with systems development
methodologies are better equipped to assist in getting the
right systems developed in the right way and budget
For Marketing
 marketing functions are hotbed of systems development
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Introduction to Information Technology
Turban, Rainer and Potter
Chapter 14 Information systems development
What’s in IT for Me? (continued …)
For Production/Operations Management
 increasingly computer-controlled and
integrated with other allied systems, from
design to logistics to inventory control to
production planning
For Human Resources Management
 new systems may require terminating
employees, hiring new employees, or changing
job descriptions
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