The Constructive Cost Model (COCOMO) is a procedural software cost estimation model developed by Barry W. Boehm. The model parameters are derived from fitting a

regression Regression or regressions may refer to: Science * Marine regression, coastal advance due to falling sea level, the opposite of marine transgression * Regression (medicine), a characteristic of diseases to express lighter symptoms or less extent ( ...

formula using data from historical projects (63 projects for COCOMO 81 and 163 projects for COCOMO II).

History

The constructive cost model was developed by Barry W. Boehm in the late 1970s and published in Boehm's 1981 book ''Software Engineering Economics'' as a model for estimating effort, cost, and schedule for software projects. It drew on a study of 63 projects at TRW Aerospace where Boehm was Director of Software Research and Technology. The study examined projects ranging in size from 2,000 to 100,000

lines of code Source lines of code (SLOC), also known as lines of code (LOC), is a software metric used to measure the size of a computer program by counting the number of lines in the text of the program's source code. SLOC is typically used to predict the am ...

, and programming languages ranging from

assembly Assembly may refer to: Organisations and meetings * Deliberative assembly, a gathering of members who use parliamentary procedure for making decisions * General assembly, an official meeting of the members of an organization or of their representa ...

PL/I PL/I (Programming Language One, pronounced and sometimes written PL/1) is a procedural, imperative computer programming language developed and published by IBM. It is designed for scientific, engineering, business and system programming. It ...

. These projects were based on the

waterfall model The waterfall model is a breakdown of project activities into linear sequential phases, meaning they are passed down onto each other, where each phase depends on the deliverables of the previous one and corresponds to a specialization of tasks. ...

of software development which was the prevalent software development process in 1981. References to this model typically call it ''COCOMO 81''. In 1995 ''COCOMO II'' was developed and finally published in 2000 in the book ''Software Cost Estimation with COCOMO II''.

Barry Boehm Barry William Boehm (May 16, 1935 – August 20, 2022) was an American software engineer, distinguished professor of computer science, industrial and systems engineering; the TRW Professor of Software Engineering; and founding director of the Ce ...

, Chris Abts, A. Winsor Brown, Sunita Chulani, Bradford K. Clark, Ellis Horowitz, Ray Madachy, Donald J. Reifer, and Bert Steece. ''