Constructive Cost Model


Constructive Cost Model

(programming)(COCOMO) A method for evaluating the cost of asoftware package proposed by Dr Barry Boehm. There are anumber of different types:

The Basic COCOMO Model estimates the effort required todevelop software in three modes of development (Organic Mode, Semidetached Mode, or Embedded Mode) using onlyDSIs as an input. The Basic model is good for quick, early,and rough order of magnitude estimates.

The Intermediate COCOMO Model an extension of the Basic COCOMOmodel. The Intermediate model uses an Effort Adjustment Factor (EAF) and slightly different coefficients for theeffort equation than the Basic model. It produces betterresults than the Basic model because the user suppliessettings for cost drivers that determine the effort andduration of the software projects. The Intermediate modelalso allows the system to be divided and estimated incomponents. DSI values and cost drivers can be chosen forindividual components instead of for the system as a whole.

The Detailed COCOMO Model differs from the Intermediate COCOMOmodel in that it uses effort multipliers for each phase of theproject. These phase dependent effort multipliers yieldbetter estimates because the cost driver ratings may bedifferent during each phase. The detailed model also providesa three-level product hierarchy and has some othercapabilities such as a procedure for adjusting the phasedistribution of the development schedule.

["Software Engineering Economics", B. Boehm, Prentice-Hall,1981].