COCOMO II is a model that allows one to estimate the cost, effort, and schedule when planning a new software development activity. It consists of three submodels, each one offering increased fidelity the further along one is in the project planning and design process. Listed in increasing fidelity, these submodels are called the Applications Composition, Early Design, and Post-architecture models. Until recently, only the last and most detailed submodel, Post-architecture, had been implemented in a calibrated software tool. As such, unless otherwise explicitly indicated, all further references on these web pages to "COCOMO II" or "USC COCOMO II" can be assumed to be in regard to the Post-architecture model.