Basic COCOMO

Basic COCOMO is a form of the COCOMO model. Cocomo may be applied to three classes of software projects. These give a general impression of the software project.

• Organic projects - are relatively small, simple software projects in which small teams with good application experience work to a set of less than rigid requirements.
• Semi-detached projects - are intermediate (in size and complexity) software project in which teams with mixed experience levels must meet a mix of rigid and less than rigid requirements.
• Embedded projects - are software project that must be developed within a set of tight hardware, software, and operational constraints.

The basic Cocomo equations take the form

E=a_b(KLOC)^b_b

D=c_bd_b

where E is the effort applied in person-months, D is the development time in chronological months, and KLOC is the estimated number of delivered lines of code for the project (expressed in thousands). The coefficients a_b, b_b, c_b and d_b are given in the following table.

 Software project ab bb 
cb db Organic 2.4 1.05 
2.5 0.38 Semi-detached 3.0 1.12 2.5 0.35 Embedded 3.6 1.20 2.5 0.32
 

Basic Cocomo is good for quick, early, rough order of magnitude estimates of software costs, but its accuracy is necessarily limited because of its lack of factors to account for differences in hardware constraints, personnel quality and experience, use of modern tools and techniques, and other project attributes known to have a significant influence on software costs.