COCOMO

COCOMO stands for COnstructive COst MOdel

COCOMO ,COnstrustive COst MOdel is static single variable model .
Barry Bohem introduced COCOMO models.
There is a hierarchical of these models.

Model 1:
Basic COCOMO model is static single-valued model that computers software development effort (and cost)
as a function of program size expressed in estimate lines of code.

Model 2 :
Intermediate COCOMO model computers software development effort as a function of program size and a set of "cost drivers"  that include subjective assessments of product ,hardware ,personnel, project attributes.

Model 3:
Advanced COCOMO model incorporates  all characteristics of the intermediate version with an assessment of the cost driver's impact on each step,like analysis ,design ,etc.

COCOMO can be applied to the following software project's categories.
Organic mode
Embedded mode

 Problem :

KLOC =10.9
E = a_b(KLOC)exp(b_b)
    =2.4 (10.9)exp(1.05)
    =29.5 person-month
D = c_b(E)exp(d_b)
     =2.5 (29.5) exp (.38)
    = 9.04 months
where ,
D is the chronological month
KLOC is the estimated number of delivered lines (expressed in thousands ) of code for project


The intermediate COCOMO model takes the following form ;

E = ai(LOC)exp(bi) X EAF
where ,
 E is the effort applied in person-month
LOC is the estimated number of delivered lines of code for the project.

The coefficient ai and the exponent bi are :
Software project      ai          bi
Organic                   3.2        1.05
Semi-detached        3.0       1.12
Embedded              2.8       1.20

(cocomo to study online)