Chapter 13 - Information Technology
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Transcript Chapter 13 - Information Technology
Computers Are
Your Future
© 2006 Prentice Hall, Inc.
Computers Are Your Future: Chapter 13
Computers Are Your Future
Chapter 13
Systems Analysis and Design
© 2006Prentice Hall, Inc.
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Computers Are Your Future: Chapter 13
What You Will Learn About
What systems analysts do
The concept of a system and its life cycle
The use of the systems development life cycle (SDLC)
The SDLC’s five phases
The mistakes of failed information systems development
projects
The activities in each of the SDLC’s five phases
The deliverables in each of the SDLC’s five phases
© 2006Prentice Hall, Inc.
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Computers Are Your Future: Chapter 13
Information Systems
The information age is all about managing the data –
to provide information and the systems to support
society’s many functions
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Computers Are Your Future: Chapter 13
Systems Analysis
The Systems Analysis is a professional who is
charged with the planning, development, and
implementation of information systems
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Computers Are Your Future: Chapter 13
Systems Analysts: Communication Counts
Systems analysts:
Are computer and problem-solving professionals who
determine an organization’s information system needs
Define the requirements needed to modify an existing
system or develop a new one
Identify alternative solutions and assist in the
development of a system
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Computers Are Your Future: Chapter 13
Systems Analysts: Communication Counts
A systems analyst’s job involves:
Communication
Understanding the organization’s mission
Understanding user needs
Documenting each step of development
Following an organized procedure
Systems development life cycle (SDLC)
© 2006Prentice Hall, Inc.
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Computers Are Your Future: Chapter 13
Systems
A system is a collection of components (hardware and
software) organized to accomplish a task
Systems have a life cycle:
Preliminary design stage
Detailed design stage
Fabrication, assembly, integration,
and test stage
Production and customer support stage
Termination and disposal stage
© 2006Prentice Hall, Inc.
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Computers Are Your Future: Chapter 13
The Systems Development Life Cycle (SDLC)
The SDLC is a model used to improve the quality of
information systems by providing an organized
approach to problem solving
The core idea of SDLC is “Ensure that each step is
performed properly before going to the next one”
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Computers Are Your Future: Chapter 13
The Systems Development Life Cycle (SDLC)
The essential services provided by information
systems include:
Recording and tracking transactions
Providing decision makers with facts and figures
Providing documentation to consumers and suppliers
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Computers Are Your Future: Chapter 13
“Classic Mistakes”
End user involvement is crucial
A problem-solving approach works best
Good project management (PMP’s) skills are needed
Documentation is necessary
Checkpoints help ensure that the project is on track
The system should be designed for growth and change
© 2006Prentice Hall, Inc.
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Computers Are Your Future: Chapter 13
The Waterfall Model
The Five Phases of the SDLC
Identify problems
and opportunities
Analyze and
document
existing system
Design system
Implement system
Support system
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Computers Are Your Future: Chapter 13
The Five Phases of the SDLC
1.
2.
3.
4.
5.
Plan: identify problems and opportunities
Analyze: analyze and document existing programs
Design: design the system
Implement: implement the system
Maintain: support the system
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Computers Are Your Future: Chapter 13
Phase 1: Identifying the Problem
and Opportunities
Recognizing the Need
Deficiencies in performance,
information quality,
economics, security,
efficiency, or service are
identified
A request goes to a steering
committee, which decides
which needs to address
A project team is appointed
and goals are set for the
project
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Computers Are Your Future: Chapter 13
Phase 1: Identifying the Problem
and Opportunities
Defining the Problem
A problem is the underlying
cause of a symptom
Determining the exact
problem is difficult
An analyst uses information
obtained from users and
makes a recommendation to
modify the existing system
or create a new system
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Computers Are Your Future: Chapter 13
Phase 1 (continued)
Examining Alternative
Solutions
The project team looks at
possible solutions
Internally developed
systems
Off-the-shelf software
Outsourcing
If a solution can be found,
the project proceeds
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Computers Are Your Future: Chapter 13
Phase 1 (continued)
Developing a Plan
The project leader formulates
a project plan
The plan specifies:
Goal and scope
All activities
Estimated time
Estimated cost
A Gantt chart is created to
provide a timeline of activities
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Computers Are Your Future: Chapter 13
Phase 1 (continued)
Determining Feasibility
Three dimensions:
Technically feasible
Operationally feasible
Economically feasible
Tangible savings include
labor costs, services, and
materials
Intangible benefits include
increased sales and better
information on which to
base decisions
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Computers Are Your Future: Chapter 13
Phase 1 (continued)
Preparing a Project Proposal
Existing system problems
are introduced
Proposed solutions are
explained
Details of the project plan
are presented
The proposal concludes with
a recommendation
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Computers Are Your Future: Chapter 13
Phase 2: Analyzing and Documenting the
Existing Information System
Analyzing the
Existing System
The existing system is
documented
Activities that should be
continued are determined
Problems not identified in
Phase 1 are pointed out
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Computers Are Your Future: Chapter 13
Phase 2: Analyzing and Documenting the
Existing Information System
Determining the New
System’s Requirements
The new system’s
requirements are precisely
stated
The requirements state the
innovations necessary for the
system to be acceptable
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Computers Are Your Future: Chapter 13
Phase 3: Designing the System
How the new system will work is the primary concern
The overall logical design of the project is looked at
How the new system’s output will look is specified
Analysts can use structural analysis and design tools:
Entity-relationship diagram (ERD)
Data flow diagram
Prototyping tool
Project and data dictionaries are created by team members
Joint application development (JAD) and computer-aided
software engineering (CASE) help improve the design phase
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Computers Are Your Future: Chapter 13
Entity-Relationship Diagram
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Computers Are Your Future: Chapter 13
Data Flow Diagram
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Computers Are Your Future: Chapter 13
Prototyping Tool
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Computers Are Your Future: Chapter 13
Phase 4: Implementing the System
Deciding to Buy or Build
Decisions are made as to
whether the system is to be
developed in-house or
outsourced
For outsourced projects the
team sends:
Request for Quotation
(RFQ)
Request for Proposal
(RFP)
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Computers Are Your Future: Chapter 13
Phase 4: Implementing the System
Developing the Software
Programmers use a program
development life cycle
(PDLC)
Testing
Two types of testing:
Application testing
Acceptance testing
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Computers Are Your Future: Chapter 13
Phase 4 (continued)
Training
Information systems contain
computer hardware/software,
knowledgeable users, and
procedures
Users are trained in one-onone training sessions
Computer-based training uses
multimedia, animation, and
programmed learning
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Computers Are Your Future: Chapter 13
Phase 4 (continued)
Converting Systems
Conversion occurs in the
following ways:
Parallel conversion
Pilot conversion
Phased conversion
Direct conversion
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Computers Are Your Future: Chapter 13
Phase 5: Maintaining the System
The new system receives ongoing assistance
A post-implementation system review determines if
the new system has met its goals
If the new system is found to be deficient, the
systems development life cycle begins again
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Computers Are Your Future: Chapter 13
Important Terms
Information Technology Steering Committee
Return on Investment (ROI)
Request for Quotation (RFQ)
Request for Proposal (RFP)
Value-Added Resellers (VARs)
Proof of Concept (POC)
Acceptance Testing
Cost Benefit Analysis
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Computers Are Your Future: Chapter 13
Chapter 13 Summary
•
•
Systems analysts help determine an organization’s
information system needs by working closely with both
users and management
Systems analysts can avoid mistakes by:
• Involving users
• Using a problem-solving approach
• Applying project management skills
• Keeping thorough documentation
• Using checkpoints
• Designing the system for growth and change
© 2006Prentice Hall, Inc.
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Computers Are Your Future: Chapter 13
Chapter 13 Summary (continued)
•
•
The systems development life cycle (SDLC) was developed
to impose order on earlier, haphazard development
processes
The SDLC’s five phases are:
• Plan: identify problems and opportunities
• Analyze: analyze and document existing programs
• Design: design the system
• Implement: implement the system
• Maintain: support the system
© 2006Prentice Hall, Inc.
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