Estimation is the calculated approximation of a result which is usable even if input data may be incomplete, uncertain, or noisy.

In statistics, see estimation theory, estimator.

In mathematics, approximation or estimation typically means finding upper or lower bounds of a quantity that cannot readily be computed precisely. While initial results may be unusably uncertain, recursive input from output, can purify results to be approximately accurate, certain, complete and noise-free.

• In project management (ie. for engineering), accurate estimates are the basis of sound project planning. Many process which have been developed to aid engineers in making accurate estimates, such as
  • compartmentalization (ie. breakdown of tasks),
  • structured planning,
  • educated assumptions,
  • identifying dependencies,
  • examining historical data,
  • estimating each task,
  • and
  • documenting the results.

Popular estimation processes include:

• Cocomo
• Proxy Based Estimation (PROBE) (from the Personal Software Process)
• Wideband Delphi
• The Planning Game (from Extreme Programming)
• Program Evaluation and Review Technique (PERT)

See also

• "Estimated" sign
• Estimation in software engineering
• Estimation theory
• Fermi problem
• Project management
• Software metric
• Wideband Delphi

External links

• Estimation chapter from "Applied Software Project Management" (PDF)
• Methvin | Estimation Software "Estimating Bidding and Project Management"

Schätzung | Szacowanie