Transcript System Flow Charts A modeling method that analysts may use to provide a graphic overview of the relationships between input, processing, and outputs.

System Flow Charts
A
modeling
method
that
analysts may use to
provide
a
graphic
overview
of
the
relationships between
input,
processing,
and
outputs
for
the whole system.
Invento
ry
file
Invento
ry
transact
ion
Invento
ry
process
ing
Invento
ry
Master
update
Invento
ry
update
report
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Function Decomposition
Modeling Method
A
function
decomposition
provides a conceptual
overview
of
all
the
activities
an
organization performs in
Business
support of its function
overall purpose.
Manufactur
Distribute
Market
e product
product
product
R&
AdvertisingR &
Maintain
Market
•
•
•
D ••
D
operations
analysis
•
•
•
Maintain Production
•
•
•
•
•
operations
parts
2
•
•
Procedure Modeling
Methods
The
modeling
methods,
such
as HIPO diagrams,
Nassi-Schneiderman
charts,
program flow charts,
psuedocode
and
structured
English, action diagrams, and
structure
charts,
are
used
to
help
model the information
system
procedures
that
eventually
become instructions
that make up program logic.
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HIPO
Diagram
Modeling
Method
HIPO
diagrams
are
used
to
hierarchically show the
inputs,
processing,
and
outputs
of
each processing module.
A
HIPO
diagram
usually
consists of three separate
and interrelated sets of diagrams :
1.
A
visual
table
of
contents
(VTOC) diagram
2. An Overview diagram
3. One or more detail diagrams
HIPO VTOC Diagrams
Identifies
the
major
procedures
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performed by the
NEW
EMPLOYEE
HIRING
1.0
System
Procedure
NEW
EMPLOYEE
DATA ENTRY
1.1
Subordinate
Procedure CHECK &
EMPLOYEE
APPLICATION
PROCESSING
1.2
MATCH
QUALIFICATION
1.21
DEPARTMENT
PERSONNEL
REPORTING
1.3
PROCESS
MATCHED
REQUEST
1.22
: VTOC for processing a payroll application
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HIPO Overview Diagrams
A
HIPO
diagram
to
depict
each
level of processing
within
the
VTOC,
with
an
overview
diagram sometimes
created
for
each
module
in
the
VTOC.
HIPO Detail Diagrams
A
HIPO
diagram
that
contains
the specific steps
involved
in
procedures
identified
in
the overview diagram.
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Nassi-Schneiderman Charts
A
procedure
modeling
method
in which each type of
control
structure
is
used
to
specify
the set of procedures
required
for
a
particular
application
using the three basic
principles
of
good
programming
:
sequence, selection, and
Select
Seque
Iterati
ion
nce
on
iteration.
Instructi
on• a
•
Instructi
on n
IF
TRUE
FALSE
Instruction
a
Instruction
b
LOOP
STATEMENT
BODY OF
LOOP
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OPEN FILE
DO WHILE THERE ARE RECORD
TO BE ENTERED
INPUT RECORD FROM
TERMINAL
VALIDATE
VALID RECORD
RECORD
YES ?
NO
WRITE TO FILE WRITE TO
ERROR FILE
CLOSE FILES
Example of Nassi-
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Program Flow Charts
procedure
diagram that
usesAgraphical
symbols
to
specify the logic
of
programming
procedures
that
express
selection,
and
iteration.sequence,
STAR
T
A,
B
Ye
s
A
A >=
B
STO
No
B
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Pseudocode
Consists
of instructions
written
in broken-English
statements
that
are
fundamentally
equivalent to their
counterparts
in a particular
computer language.
Open the files
Read a COMMISSION record
Do until end of file
Compute commission
Print a detail line
Read a COMMISSION
record
ENDDO
Close the files
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End of program
Structured English
A procedure
method
similar inmodeling
use to
pseudocode,
but
less
cryptic
in
its
statement.
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Structure Charts
A structure
chart (STC) is a
graphical
modeling
method
that
depicts
the
procedure
logic
of programs
in a
basic
consistent with the
layoutformat
of structured
programs.
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Basic symbols for
structure charts
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Structure chart example
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Structure chart
Process
Commis
sions
Read
Commis
sion
Record
Process
Commis
sion
Print
Speci
al
Lette
r
Print
Awar
d
List
Calculat
e
Commis
sion
Read
Commi
ssion
Record
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Conversion from DFD to
Course
Descriptio
Structure
charts
n
2
Course
Record Read
Course
Master
Course
Number
Of Credits
Cours
e
Recor
d
4
Course Calcul
ate
Number GPA.
1
Grade
Record Read
Grade file
Grade
Recor
d
Course
Grade
Student
Number
Student
Master
3
Student
Record Read
Stude
nt
Recor
d
DFD Level
GPA.
5
Print
Stude
nt
Repor
t
Student
Report
Card
Student
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Grade
Point
Average
5.1
Format
Student Name
Student
and Address
Name
and
Address
line
CourseCourse
GradeDescriptio
n
5.2
5.3
Format
Format
Course
Grade
Point
Grade
Average
line
line
Course
Grade
Line
5.4
Write
Name and Report
Address LineCard
line
Child
Grade Point
Average Line
Student
Report
Card
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Produce
Student
Report Card
Prepare
Student
Report Card
Read
Grade
Recor
d
Read
Cours
e
Recor
d
Read
Stude
nt
Recor
d
Calculate Print
Grade
Point Student
Average Report
Card
Format
Student
Name
and
Address
Line
Format
Course
Grade
Line
Format
Grade
Point
Average
Line
A structure chart for producing
Write
Repor
t
Card
Line
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