Transcript System Development Life Cycle (SDLC) A series of steps completed over a period of time by analysts in the course of a.

System
Development
Life
Cycle (SDLC)
A
series
of
steps
completed
over
a
period of time by
analysts
in
the
course
of
a
system
development or
maintenance project.
The
main
steps
of
the
SDLC
include
Analyzing
how
the
current
system meets users’
information needs
Providing
a
design
for
a
new
system or a modification
of
an
existing
system
to
meet
these needs
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System Development Life
Cycle
Phase 1 : Preliminary
Investigation
Phase 2 : System Analysis
Phase 3 : System Design
Phase 4 : System Development
Phase 5 : System
Implementation and evaluation
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Systems
Request
Phase 1
Preliminar
y
Investigati
on
Prelimi
nary
Investig
ation
Report
STO
P
Replac
e IS
Phase
2
System
s
Analysi
s
System
Require
ments
Docume
nt
STO
P
STO = Terminate
P Development
Phase 3
Systems
Design
System
Design
Specific
ation
STO
P
Phase 4
Systems
Developm
ent
Complet
e
Functioni
ng IS
Waterfall model
Phase 5
Systems
Implementati
on
and
Evaluation
Operatio
nal IS
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• Phase 1 : Preliminary
Investigation (Feasibility Study)
A written request from
management or an end user
triggers the start of the systems
development life cycle. This
written request is called a system
request.
The purpose of the preliminary
investigation phase is to
identify clearly the nature and scope of
the problems mentioned
in the systems request. Because
identifying the problem is the
focus of the preliminary investigation,
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• Phase 2 : System Analysis
The
purpose
of
the
systems
analysis phase is to
learn
exactlysystem,
what takes
the current
to place in
determine
fullytake
document in
detail whatand
should
place,
and to maketo
recommendations
management on
the
alternative
solutions
and
their
costs. Through the
process
of fact-finding
or
requirements
determination,
You
first define
all the functions
performed
by the
current
information
system. At the
same time,
you
determine what modifications are
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The life
endcycle
product
you create
for this
phase
is
the
system
requirements
document, which documents
all
end
user
and
management
requirements, all
alternative
plans
and
their
costs,
and your
recommendations
to
management.
After
you
present
your
results
from
this
phase
to
management, management
decides on the best alternative.
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• Phase 3 : System Design
The
purpose
of
the
systems
design phase is to
determine
how
to
construct
the
information system to best
satisfy
the
documented
requirements. You must design all
required
information
system
outputs, files, inputs,
application
software
programs,
and manual procedures.
Also,
you
must
design
the
internal
and external controls,
which
are
computer-based
and
manual steps that
guarantee
the
information
system
will be reliable,
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The
design
is
documented
in
the system design
specification
and
is
presented
to
the management and the
end
users
for
their
review
and
approval. Management
and
end
user
involvement
is
critical so there is no
misunderstanding
about
what
the
IS is to do, how it will
do
it,
and
what
it
will
cost,
After
all systems design steps
have
been completed
developments
is not and if the
terminated,
you
then
enter
the
next phase, system
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•development
Phase 4 : System
System
development
is
the
phase during which
the
information
system
is
actually constructed:
application
programs
are
written,
tested, and
documented;
operational
documentation
and
procedures
are
completed;
and
end user and
management
review
and
approval is obtained. The end
product
of
this
phase
is
a
completely functioning and
documented
information
system.
As is true with all
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•implementation
Phase 5 : System
and
evaluation
After
the
system
development
phase is completed,
you
then
proceed
to
systems
implementation. Activities
for
this phase
conversion
of data
to the include
new
system’s
files,
final
training
of
the
end users, and the
transition
from
the
old
system
to
the new system. It is at
this
point
that
the
end
users
and
management actually
begin to use the constructed IS.
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The
of if
these
is to purpose
determine
the evaluations
information
system
proposed, and
if theoperates
costs as
and benefits are as anticipated.
•operation
After the SDLC: system
During
the systems
operation
phase,
changes
will
need
to be made
to These
the
information
system.
changes
are classified
as either
maintenance
or
enhancements.
Maintenance
changes are made
to correct
errors
or
to
conform
with
government requirements.
Enhancements
are modifications
that add or change
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1
Identifying
problems,o
pportunitie
s, and
7
Implemen objectives
ting and
evaluating
the
6 Testing
system
and
maintainin
g the
system
2
Determinin
g
information
requirement3 Analyzing
system
s
needs
5
Developin
g and
document
ing
software
4
Designing
the
recommen
ded system
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Syste
ms
plan
ning
New, related problem
or
requirement
Syste New implementation
ms
alternative or
requirement
supp
Impleme
ort
ntation
error
(bug)
Syste
Systems
ms
implemen
desig
tation
n
Obsolete
system
Syste
ms
analy
sis
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The PIECES Framework by James
Wetherbe
P The need to improve
performance.
I
The need to improve
Information(or data).
E The need to improve economics
or control costs.
C The need to improve control and
security.
E The need to improve efficiency of
people and machines.
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