Process-of-Program-Development-process.pdf

CT 8 PROGRAMMING

1. PROCESS OF PROGRAM DEVELOPMENT
PROCESS

2. THEVARIOUS STAGESINTHE
DEVELOPMENT OFACOMPUTER
PROGRAMARE:
1.Problem Definition
2.Program Design
3.Coding
4.Debugging
5.Testing
6.Documentation
7.Maintenance
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3. 3
INTRODUCTION
H O W W E D I D L A S T Y E A R
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4. PROBLEM
DEFINITION
L E T ’ S D I V E I N
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5. 5
•Thefirststepintheprocessofprogramdevelopmentis
thethoroughunderstandingandidentificationofthe
problemforwhichistheprogramorsoftwareistobe
developed.
•Inthissteptheproblemhastobedefinedformally.
•AllthefactorslikeInput/output,processingrequirement,
memoryrequirements,errorhandling,interfacingwith
otherprogramshavetobetakenintoconsiderationinthis
stage.

6. T H I N K W E L L
Program Design

7. •Thenextstageistheprogramdesign.Thesoftware
developermakesuseoftoolslikealgorithmsand
flowchartstodevelopthedesignoftheprogram.
•Algorithm
•Flowchart

8. CODING
L O O K I N G A H E A D
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9. •Oncethedesignprocessiscomplete,theactualcomputerprogramiswritten,
i.e.theinstructionsarewritteninacomputerlanguage.
•Codingisgenerallyaverysmallpartoftheentireprogramdevelopmentprocess
andalsoalesstimeconsumingactivityinreality.
•Inthisprocessallthesyntaxerrorsi.e.errorsrelatedtospelling,missing
commas,undefinedlabelsetc.areeliminated.
•Foreffectivecodingsomeoftheguidelineswhichareappliedare:
•Useofmeaningfulnamesandlabelsofvariables,
•Simpleandclearexpressions,
•Modularitywithemphasisonmakingmodulesgeneralized,
•Makinguseofcommentsandindentingthecodeproperly,
•Avoidingjumpsintheprogramtotransfercontrol.

10. 10
DEBUGGING
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11. •Atthisstagetheerrorsintheprogramsaredetectedandcorrected.
•Thisstageofprogramdevelopmentisanimportantprocess.
Debuggingisalsoknownasprogramvalidation.
•Somecommonerrorswhichmightoccurintheprogramsinclude:
•Uninitializationofvariables.
•Reversingoforderofoperands.
•Confusionofnumbersandcharacters.
•Invertingofconditionsegjumpingonzeroinsteadofonnotzero.

12. TESTING
•Theprogramistestedonanumberofsuitabletestcases.
•Atestplanoftheprogramhastobedoneatthestageofthe
programdesignitself.
•Thisensuresathoroughunderstandingofthespecifications.
•Themosttrivialandthemostspecialcasesshouldbe
identifiedandtested.
•Itisalwaysusefultoincludethemaximumandminimum
valuesofallvariablesastestdata.

13. DOCUMENTATION
L E T ’ S D I V E I N
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14. •Documentationisaveryessentialstepinthe
programdevelopment.
•Documentationhelptheusersandthepeople
whomaintainthesoftware.
•Thisensuresthatfuturemodificationifrequired
canbedoneeasily.Alsoitisrequiredduring
redesigningandmaintenance.

15. MAINTENANCE
L E T ’ S D I V E I N
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16. •Updatingandcorrectionoftheprogramforchanged
conditionsandfieldexperienceisaccountedforin
maintenance.
•Maintenancebecomesessentialinfollowingsituations:
•Changeinspecification,
•Changeinequipment,
•Errorswhicharefoundduringtheactualexecutionof
theprogram.