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System Flow Charts A modeling method that analy sts may use to
provide a graphic overview of the relationships between input, processing, and outputs for the whole system.Inventory
file
InventoryMasterupdate
Inventorytransaction
Inventoryupdatereport
Inventoryprocessing
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Function Decomposition Modeling Method
A function decomposition provides a conceptual overview of all the activities an organization performs in support of its overall purpose.
Business function
Manufacture product
Distribute product
Market product
Maintain operations
R & D
Market analysis
Advertising
R & D
Maintain parts
Production operations
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Procedure ModelingMethods
The modeling methods, such as HIPO diagrams,- Nassi Schneiderman charts, p rogram flow charts,
psuedocode and structured En glish, action diagrams, and structure charts, are used to h elp model the information
system procedures that event ually become instructions that make up program logic.
Program logic
Refers to the way programs ex ecute, sometimescal l ed a program’s procedur e model.
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HIPO Diagram ModelingMethod HIPO diagrams are used to hier archically show the
inputs, processing, and output s of each processing module. A HIPO diagram usually consist s of three separate
and interrelated sets of diagra ms : 1 . A visual table of contents ( VTOC) di agr am
2 . An Overview diagram 3. One or more detail diagrams
HIPO VTOC Diagrams Identifies the major procedures performed by the
system and the subordinate prooooooo ooooooooo oosuccessfully complete the maj or procedure.
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NEWEMPLOYEEHIRING 1.0
EMPLOYEEAPPLICATIONPROCESSING 1.2
NEWEMPLOYEEDATA ENTRY 1.1
DEPARTMENTPERSONNELREPORTING 1.3
PROCESSMATCHEDREQUEST 1.22
CHECK &MATCHQUALIFICATION 1.21
Figure : VTOC for processing a payroll application
System
Procedure
Subordinate Procedure
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HIPO Overview Diagrams A HIPO diagram to depict eachooooo oo oooooooooo ooo ooo oo o ooo oo oooooo, ew diagram sometimes
cr eat ed f or each module in th eVTOC.
HIPO Detail Diagrams A HIPO diagram that contains t he specific steps
i nvol ved in procedures identifi ed 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 spe cify the set of proceduresoooooooo for a particular applic ation using the three basic
principles of good programmin oooooooooo ooo: , ,.
Sequence Selection IterationInstruction aInstruction n
• • IF
TRUE FALSEInstruction a Instruction b
LOOP STATEMENT
BODY OFLOOP
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OPEN FILEDO WHILE THERE ARE RECORD TO BE ENTEREDINPUT RECORD
FROM TERMINALVALIDATE RECORDVALID
RECORD ?YES
NOWRITE TO FILE
WRITE TOERROR FILE
CLOSE FILES
Example of Nassi-Schneiderman chart
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Program Flow Charts A procedure diagram that use s graphical symbols
oo specify the logic of progra mming procedures thatexpress sequence, selection, oooooooooo. STA
RT
A , B
A >= B
A
STOP
B
Yes
No
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Pseudocode Consists of instructions writte -n in broken English
statements that are fundame ntally equivalent to their counterparts in a particular co mputer language.
Open the filesRead a COMMISSION recordDo until end of file
Compute commissionPrint a detail lineRead a COMMISSION record
ENDDOClose the filesEnd of program
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Structured English A procedure modeling metho d si mi l ar i n use t o
pseudocode, but less cryptic i n its statement.
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Structure Charts A structure chart (STC) is a graphical modeling
method that depicts the proce dure logic of programs in a basi c f or mat consistent with the layout of structured
programs.
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PrintAwardList
PrintSpecialLetter
CalculateCommission
ReadCommissionRecord
ProcessCommission
ReadCommissionRecord
ProcessCommissions
Structure chart
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Conversion from DFD to Structure charts
1ReadGradeRecord
2ReadCourseRecord
3ReadStudentRecord
5PrintStudentReport
4CalculateGPA.
Course Master
Grade file
Student Master
Course Record
Grade Record
StudentRecord
Course Number
StudentNumber
Course Grade
Course NumberOf Credits
GPA.
Course Description
Student
StudentReportCard
DFD Level 0
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5.1FormatStudentName and
Address line
5.2FormatCourseGrade line
5.4Write
ReportCard line
5.3FormatGrade PointAverage
line
Course Description
Course Grade
Grade PointAverage
Grade PointAverage Line
StudentReportCard
Student Nameand Address
CourseGrade Line
Child diagram
Name andAddress Line
18A structure chart for producing student report cards
ReadGradeRecord
ReadCourseRecord
ReadStudentRecord
CalculateGrade Point
Average
Print StudentReport Card
Format StudentName andAddress Line
ProduceStudentReport Card
PrepareStudentReport Card
Format CourseGrade Line
Format Grade PointAverage Line
WriteReportCard Line