Transcript DAC Presentation kit

Introduction to Systems
Analysis and Design
Objectives
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
Understand the fundamental SDLC and its four
phases
Understand the evolution of systems development
methodologies
Be familiar with the different roles on the project
team
What ?

System Development
Life Cycle :

Process of how an
Information System
can support business
needs, designing the
system, building it,
and delivering it to
users
Why ?
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Facts :
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A survey by the Standish Group in 1996 found that
42% of all corporate IS project were abandoned
before completion
A study by the General Accounting in 1996 found that
53% of all US Government IS projects were
abandoned. The rest are delivered to the user
significantly late, cost far more than planned, and
have fewer features than originally planned
Major Causes of Project Failure
A real estate group in the federal government
cosponsored a data warehouse with the IT department.
Why didby
theITsystem
fail? Why
A formal proposal was written
in which
costswould
were
company
spend
moneywas
and time on
estimated at $800.000, athe
project
duration
a project
and
then
cancel it? What
estimated to be eight months,
and
the
responsibility
for
could have been done to prevent this
funding was defined as the
business unit’s.
The IT department proceeded with the project
before it even knew if the project had been accepted.
The project actually lasted two years because
requirements gathering took nine months instead of one
and a half,the planned user base grew from 200 to
2.500 and the approval process to buy technology for
the project took a year. Three weeks prior to technical
delivery, the IT director canceled the project. This failed
endeavor cost the organization and taxpayers $2,5
million.
No SDLC
Advantages
 Time
 A clear purpose
Disadvantages
 Lack of proper
documentation

Hard to handle complex
system
With SDLC
Advantages
 Developers know what
should and should’nt be
built


Clear documentation
Easier to maintain
program
Disadvantages
 Different between what’s
written in paper and
what’s actually
implemented
 Limits developer’s
creativity
Conclusion
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Without an SDLC Model to follow, developers can
have a free hand of developing software. However,
development of these software doesn’t have a clear
view and it will never be viable in any business
model.
As long as the laid out plans of SDLC are followed,
the usability and success of the software is ensured.
Maintenance and development of the software is
also possible since parts could be possibly be reused
in different programs.
Key Person of SDLC
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Is the key person in SDLC
The goal is not to create
a wonderful system, but
to create value for
organization
Have to clearly
understand how the
system would fit the
organization’s goals,
current business process,
and other information
systems to provide values
SDLC Phases
Analysis
Planning
Implementation
Design
Each phase is composed of a series of
steps, which rely upon techniques that
produce deliverables
SDLC Phases (2)
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Planning
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Analysis
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Who, what, when, where will the system be?
Design
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Why build the system?
How will the system work?
Implementation
 System
delivery
Phase 1 : PLANNING
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Identifying business value
Analyze feasibility
Develop work plan
Staff the project
Prepare to control and direct project
OUTPUT : Project Plan
Phase 2 : ANALYSIS
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Developing analysis strategy
Gathering requirements
Combining analyses, system concept, and models
OUTPUT : System Proposal
Phase 3 : DESIGN
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Developing design strategy
Designing system architecture : hardware, software,
network infrastructure, and interface design
Developing database and file specifications
Building program design
OUTPUT : System Specification
Phase 4 : IMPLEMENTATION
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System construction : developing and testing the
system
System installation
Establish a support plan for the system
Process
Product
Planning
Project Plan
Analysis
System Proposal
Design
Implementation
System
Specification
New System and
Maintenance Plan
System Development
Methodologies
What is a methodology ?
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A formalized approach to implementing the SDLC.
Paradigm :
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Process-centered
Data-centered
Object oriented
Methodology Categorization
Structured
Design
RAD
Agile
Waterfall
Phased
Extreme
Programming
Parallel
Prototyping
Scrum
Throwaway
Prototyping
Dynamic
Systems
Development
Method
Methodology : Waterfall
Pros
Identifies systems
requirements long
before programming
begins
Cons
Design must be
specified on paper
before programming
begins
Long time between
system proposal and
delivery of new
system
Methodology : Parallel
Rapid Application Development (RAD)
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Adjusting the SDLC phases to get some part of the
system developed quickly
Most RAD-based methodology recommend that
analysts use special techniques and computer tools
Methodology : Phased Dev.
Methodology : Prototyping
Methodology : Throwaway Prototyping
Agile Development
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Focus on streamlining the SDLC by eliminating much
of the modeling and documentation overhead and
time spent on those task.
Methodology : XP
Methodology : Scrum
Methodology : Dynamic System
Development Method
How to select it ?
PROJECT ROLES
Project Team Roles
References
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http://en.wikipedia.org/wiki/Systems_Development_
Life_Cycle
Dennis, A. 2005. System Analysis and Design with
UML version 2.0.