According to SEI, organizations that acquire software intensive systems should have a corporate memory or historical database and a process for calibrating their cost models to reflect demonstrated performance of similar past projects. The act of calibration standardizes a model. Many models are developed for specific situations and are, by definition, calibrated to that situation. Such models usually are not useful outside of their particular environment. The act of calibration is needed to increase the accuracy of one of these general models by making it temporarily a specific model for whatever product it has been calibrated.
Calibration is in a sense customizing a generic model.
Using historical data as a basis for customizing or calibrating a tool is essential. Insure that information for current project development efforts are saved for future reference. At a very minimum, use software life cycle model phases and activities as a basis for collecting and maintaining project envelopment information for future tool use. Once calibration of the model is completed, model validation in accordance with FAA CEH, chapter 12, section 12.4.2 is necessary to establish the model s accuracy.