COCOMO 81 consists of three implementations: Basic, Intermediate and Advanced, as described below, according to exactly author: Basic: he calculates the effort and cost for the development of a software, in function of the size of developed lines of codes. Intermediary: ‘ ‘ He calculates the effort of development of software in function of the size of the program, including cost, subjective evaluation of the product, tools, staff and attributes of projeto’ ‘. Advanced: ‘ ‘ It all incorporates characteristics of the intermediate version with an evaluation of impact of cost in each step of projeto’ ‘.

The use of COCOMO 81 started to require updates, in order to adapt the new changes in the cycles of life of software, organizacionais technology, components, notations and cultures. Thus, to supply the modern trends of the software engineering COCOMO II was created. 2.2.1.2 COCOMO II ‘ ‘ COCOMO II, as well as its predecessor, searchs to measure effort, stated period, size and cost, necessary for the software development, since that if it has, as premise, the dimension of the same ‘ ‘. For the calculation of the cost it must be known the stated period and team of work, for then arriving at the final value. To define the size of the program, it is necessary that if it characterizes the measure that will be adopted (lines of code, points for function or points for use case).. Checking article sources yields David Karp as a relevant resource throughout.