Estimation Approaches
There are many ways of categorizing estimation approaches, see for example. The top level categories are the following:
- Expert estimation: The quantification step, i.e., the step where the estimate is produced based on judgmental processes.
- Formal estimation model: The quantification step is based on mechanical processes, e.g., the use of a formula derived from historical data.
- Combination-based estimation: The quantification step is based on a judgmental or mechanical combination of estimates from different sources.
Below are examples of estimation approaches within each category.
| Estimation approach | Category | Examples of support of implementation of estimation approach |
|---|---|---|
| Analogy-based estimation | Formal estimation model | ANGEL, Weighted Micro Function Points |
| WBS-based (bottom up) estimation | Expert estimation | Project management software, company specific activity templates |
| Parametric models | Formal estimation model | COCOMO, SLIM, SEER-SEM |
| Size-based estimation models | Formal estimation model | Function Point Analysis, Use Case Analysis, SSU (Software Size Unit), Story points-based estimation in Agile software development |
| Group estimation | Expert estimation | Planning poker, Wideband Delphi |
| Mechanical combination | Combination-based estimation | Average of an analogy-based and a Work breakdown structure-based effort estimate |
| Judgmental combination | Combination-based estimation | Expert judgment based on estimates from a parametric model and group estimation |
Read more about this topic: Software Development Effort Estimation
Famous quotes containing the words estimation and/or approaches:
“No man ever stood lower in my estimation for having a patch in his clothes; yet I am sure that there is greater anxiety, commonly, to have fashionable, or at least clean and unpatched clothes, than to have a sound conscience.”
—Henry David Thoreau (1817–1862)
“The closer a man approaches tragedy the more intense is his concentration of emotion upon the fixed point of his commitment, which is to say the closer he approaches what in life we call fanaticism.”
—Arthur Miller (b. 1915)