Lead Black Slide
Chapter 13
Developing and Managing
Information Systems
© 2001 Business & Information Systems 2/e
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Our Agenda
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People in Information Systems
Development
The System Development Process
System Development Tools
A Case Study of Information Systems
Development
Other System Development Approaches
© 2001 Business & Information Systems 2/e
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Our Agenda (cont’d.)
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Individual Information Systems
Development
Electronic Commerce Systems
Development
Business Process Reengineering
© 2001 Business & Information Systems 2/e
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Learning Objectives
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Explain the roles of the people who are
involved in information system
development.
Outline the phases and steps in the
information system development
process.
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Learning Objectives (cont’d.)
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Describe the user’s involvement in each
phase of the system development
process.
Explain the purpose of common tools
used for system development.
Explain the use of prototyping and rapid
application development in system
development.
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Learning Objectives (cont’d.)
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Explain how the system development
process can be adapted to the
development of individual information
systems.
Describe the process of developing
electronic commerce systems.
Describe the purpose of business
process reengineering.
© 2001 Business & Information Systems 2/e
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People in Information
System Development
Developing and Managing
Information Systems
© 2001 Business & Information Systems 2/e
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People in Information Systems
Development
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Systems analysts follow a step-by-step
process to develop information systems.
Information systems are usually
developed by a group of people who
form a project team.
© 2001 Business & Information Systems 2/e
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The System Development
Process
Developing and Managing
Information Systems
© 2001 Business & Information Systems 2/e
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The Systems Development
Process
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The system development process,
which also called the System
Development Life Cycle (SDLC) is
divided into five main phases:
1.
2.
3.
4.
5.
System
System
System
System
System
planning
analysis
design
implementation
maintenance
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System Planning
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System planning is the phase in which
the systems analyst decides whether a
new information system should be
developed.
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The systems analyst conducts a feasibility
analysis.
A cost/benefit analysis is prepared.
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System Analysis
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During system analysis, the analyst
studies the existing and determines what
the new system must do.
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Develop user requirements
Develop a conceptual design
Evaluate hardware and software alternatives
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Packaged software
Custom software
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System Design
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During system design, the analyst
specifies how the new system will
function.
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Understanding what the new system must do
Understanding how the system will do it
Describing design details including layouts of
screens, forms and reports; specifications for
all hardware; descriptions of all programs.
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System Implementation
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During system implementation, the
systems analyst acquires the
components of the system – such as
programs – tests the system, and
changes over to the new system.
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System Implementation
(cont’d.)
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Four methods of converting to the new
system:
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Plunge – old system is turned off, new one is
turned on.
Phased – new system is divided into parts with
one part phased in at a time.
Pilot – new system is installed in a part of the
organization.
Parallel – old and new systems are used
simultaneously for a period of time.
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System Maintenance
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System maintenance involves modifying
the system during its life to meet new
requirements.
Maintenance is required for three
reasons:
1. Errors found that were not detected in
testing
2. A new function is to be added to the system
3. The requirements have changed
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System Development Tools
Developing and Managing
Information Systems
© 2001 Business & Information Systems 2/e
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System Development Tools
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Data Flow Diagrams (DFD)
Entity-Relationship diagram (ER)
CASE tools
© 2001 Business & Information Systems 2/e
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Data Flow Diagrams
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A tool many analysts use to show the flow of
data in an information system.
The diagram uses symbols with different
shapes to indicate how data flows in the
system. They are:
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Process – a rounded corner rectangle
External entity – a rectangle
Data store – an open rectangle
Data flow – an arrow
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Entity-Relationship Diagram
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An entity is something about which data
is stored in a database.
A relationship is an association between
entities.
An entity-relationship diagram shows
the entities and relationships between
entities in a database.
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CASE Tools
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CASE – Computer Aided Software
Engineering – tools are computer based
tools such as those for system
development.
© 2001 Business & Information Systems 2/e
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A Case Study in Information
System Development
Developing and Managing
Information Systems
© 2001 Business & Information Systems 2/e
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A Case Study in Information
Systems Development
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Sportswear Enterprises is considering
requesting a sales system analysis. The
case study considers the five steps in
the system development life cycle.
© 2001 Business & Information Systems 2/e
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Other System Development
Approaches
Developing and Managing
Information Systems
© 2001 Business & Information Systems 2/e
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Other System Development
Approaches
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Three alternative approaches to
developing information systems:
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Prototyping
Rapid Application Development (RAD)
Object-oriented analysis and design
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Prototyping
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Prototyping involves the systems
analyst obtaining informal and
incomplete requirements for the system
and developing a prototype, which is a
partial version of the system that acts
like the real system but may not
perform all the required functions of the
system.
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Rapid Application
Development
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Prototyping is used to determine user
requirements.
CASE tools speed up the analysis and
design.
The prototype is often developed into
the final system.
Significant user involvement is required.
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Object-Oriented Analysis and
Design
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Object-oriented analysis and design
involves combining the data and
processing methods usually specified in
the DFD and ER diagrams respectively.
They are combined to form an object.
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Individual Information
System Development
Developing and Managing
Information Systems
© 2001 Business & Information Systems 2/e
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Individual Information System
Development
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The five steps of the SDLC serve as a
general guide.
Individual information system planning
starts when the user recognizes a
problem or a need.
Must consider whether personal
technical skills are adequate.
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Electronic Commerce System
Development
Developing and Managing
Information Systems
© 2001 Business & Information Systems 2/e
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Electronic Commerce System
Development
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While similar to the steps in the SDLC,
there are notable differences:
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In e-commerce systems, the main user is
the customer.
Software selection is limited to the special
e-commerce software.
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Electronic Commerce System
Development (cont’d.)
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Design of an e-commerce system
involves two main parts:
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Front end – is what the customer sees
when they use the system.
Back end – provides the capabilities
necessary for completing the customer’s
order including inventory control and
product distribution.
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Electronic Commerce System
Development (cont’d.)
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Publishing the system is the process of
setting up the system on a server and
making it available through the
Internet.
© 2001 Business & Information Systems 2/e
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Business Process
Reengineering
Developing and Managing
Information Systems
© 2001 Business & Information Systems 2/e
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Business Process Reengineering
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Business Process Reengineering (BPR)
involves completely redesigning the
business processes, which are groups of
activities or tasks that accomplish things
for a business.
BPR is not gradual improvement, but
rather radical redesign of business
processes.
© 2001 Business & Information Systems 2/e
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Developing and Managing
Information Systems
Key Terms
© 2001 Business & Information Systems 2/e
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Key Terms
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Business Process
Business Process
Reengineering (BPR)
CASE
Conceptual Design
Cost/Benefit Analysis
Data Flow Diagram
(DFD)
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© 2001 Business & Information Systems 2/e
Entity-Relationship (ER)
Diagram
Feasibility Analysis
Legacy System
Object-Oriented
Analysis and Design
Outsourcing
Packaged Software
Project Team
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Key Terms (cont’d.)
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Prototype
Prototyping
Rapid Application
Development (RAD)
System Analysis
System Design
System Development
Life Cycle (SDLC)
System Implementation
© 2001 Business & Information Systems 2/e
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System Maintenance
System Planning
Systems Analysis
User Requirements
40
Summary
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People in Information Systems
Development
The System Development Process
System Development Tools
A Case Study of Information Systems
Development
Other System Development Approaches
© 2001 Business & Information Systems 2/e
41
Summary (cont’d.)
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
Individual Information Systems
Development
Electronic Commerce Systems
Development
Business Process Reengineering
© 2001 Business & Information Systems 2/e
42
Final Black Slide