ISBN : 978-81-963532-2-3 (E-Book) toBoehm,softwarecostestimationshouldbedonethroughthreestages:BasicCOCOMO,Intermediate COCOMO,and Complete COCOMO. BasicCOCOMOModel ThebasicCOCOMOmodelgivesanapproximateestimateoftheprojectparameters.ThebasicCOCOM Oestimation model is given bythefollowingexpressions: a Effort= a 1 1 х(KLOC) PM b 2 Tdev= b x(Effort) Months Where 2 • KLOCistheestimatedsizeofthesoftwareproductexpressedinKiloLinesofCode, • a, a,b, bareconstants foreachcategoryof softwareproducts, 1 2 1 2 • Tdevistheestimatedtimetodevelopthesoftware,expressedinmonths, • Effortisthetotaleffortrequiredtodevelopthesoftwareproduct,expressedinpersonmonth s (PMs). The effort estimation is expressed in units of person-months (PM). It is the area under thepersonmonth plot (as shown in fig. 33.1). It should be carefully noted that an effort of 100 PMdoes not imply that 100 persons should work for 1 month nor does it imply that 1 person shouldbe employed for 100 months, but it denotes the area under the person-month curve (as shown infig.33.1). 162 Software Engineering Keerthana P, Manasa KN, Ganga D Bengal
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