There are also universal parametric estimating systems that generate, internal to the model, appropriate expressions of CERs for a broad range of products or systems. These models perform a mathematical extrapolation of past experience in order to predict cost. Computerized parametric cost estimating models often contain many mathematical equations relating the input variables to cost. Each set of input parameters uniquely defines the item of interest for cost modeling. The calibration process simulates past product history and organizational traits.
Models are also available for computing operation and support costs of hardware in the field.
Also, models used for the development and maintenance costs of computer software are available. A model is a representation of a real-life system. In the case of cost estimating, a parametric model is a system of data, equations, and inferences presented in mathematical form to represent or describe the cost of an item. It can also be designed to estimate items as small as modules or components, or as large as subsystems, systems, total programs, or large development activities.