Estimation is generally an approximate or uncertain calculation of a result, often based on approximate, uncertain, incomplete, or noisy data.
For an account of statistical estimation, see estimator and estimation theory.
The ability to accurately estimate the time/cost taken for a project to come to its successful conclusion has been a serious problem for software engineers. The use of repeatable, clearly defined and well understood software development process has in recent years shown itself to be the most effective method of gaining useful historical data that can be used for statistical estimation. In particular, the act of sampling more frequently, coupled with the loosening of constraints between parts of a project, has allowed more accurate estimation and more rapid development times.
There is a discussion of estimation at [1]
See also
