COCOMO II (COnstructive COst MOdel) is an objective cost model for planning and executing software projects. It is an important ingredient for managing software projects or software lines of business. A cost model provides a framework for communicating business decisions among the stakeholders of a software effort. COCOMO II supports contract negotiations, process improvement analysis, tool purchases, architecture changes, component make/buy tradeoffs and several other return-on investment decisions with a credible basis of estimate. COCOMO II incorporates several field-tested improvements to both broaden its applicability and improve its estimating accuracy for modern software development approaches.