parametric model In statistics, a parametric model or parametric family or finite-dimensional model is a particular class of statistical models. Specifically, a parametric model is a family of probability distributions that has a finite number of parameters. Def ...

is a set of related mathematical equations that incorporates variable parameters. A

scenario In the performing arts, a scenario (, ; ; ) is a synoptical collage of an event or series of actions and events. In the ''commedia dell'arte'', it was an outline of entrances, exits, and action describing the plot of a play, and was literally p ...

is defined by selecting a value for each parameter. Software project managers use software parametric models and parametric estimation tools to estimate their projects' duration, staffing and cost. In the early 1980s refinements to earlier models, such as PRICE S and SLIM, and new models, such as SPQR, Checkpoint, ESTIMACS,

SEER-SEM SEER for Software (SEER-SEM) is a project management application used to estimate resources required for software development. History 1966 System Development Corporation Model based on regressions. 1980 Don Reifer and Dan Galorath paper whic ...

COCOMO The Constructive Cost Model (COCOMO) is a procedural software cost estimation model developed by Barry W. Boehm. The model parameters are derived from fitting a regression formula using data from historical projects (63 projects for COCOMO 81 a ...

and its commercial implementations PCOC, Costimator, GECOMO, COSTAR and Before You Leap emerged. The prime advantage of these models is that they are objective, repeatable, calibrated and easy to use, although calibration to previous experience may be a disadvantage when applied to a significantly different project. These models were highly effective for

waterfall model The waterfall model is a breakdown of project activities into linear sequential phases, meaning they are passed down onto each other, where each phase depends on the deliverables of the previous one and corresponds to a specialization of tasks. ...

, version 1 software projects of the 1980s and highlighted the early achievements of parametrics. As systems became more complex and new languages emerged, different software parametric models emerged that employed new cost estimating relationships, risk analyzers, software sizing, nonlinear software reuse, and personnel continuity.

References

{{reflist Business software Software project management Project management software Software metrics