Introduction
One of the most common desires in software development projects is to accurately determine in advance the total cost of
the project. With cost and schedule overruns being the industry norm, that desire is understandable. However, the
current state of software development practice isn't a predictive science, as clearly evidenced by the vast array of
project failures. That said, it is still useful to attempt some estimation of project costs, then calibrate those
estimates based on actual findings as the project progresses.
Here are some techniques that you may find useful in estimating software project effort. Choose one or a combination
that is appropriate to your project.
Agile Estimation
This guideline explains the technique described by [COH05]. It defines concepts such as project size, team velocity, and effort.
For more information, see Agile Estimation.
Use-Case Points
This technique originated from on work done at Objective Systems SF AB, and was first proposed in a 1993 paper by
Gustav Karner entitled Resource Estimation for Objectory Projects. This technique enables the estimation of the
resources needed to develop a software system by using the elements of the use-case model as a basis for that
estimation. The use-case points (UCP) that are derived from this method can then be used to determine the equivalent
function point (FP) count. Function Points (FP) are a common technique for estimations, proposed by Albrecht A. J.
(1979), Measuring application development productivity.
For more information, see The Estimation of Effort Based on Use Cases.
Wideband Delphi
Originating at the Rand Corporation in 1948, this technique began as the Delphi estimation method. The basic technique
called upon a small team of experts to anonymously generate individual estimates from a problem description and reach
consensus on a final set of estimates through iteration.
In the early 1970s, Barry Boehm and his Rand colleagues extended the basic method to include more estimation team
interaction, which resulted in the Wideband Delphi method; see Software Engineering Economics.[BOE81]. Mary Sakry and Neil Potter of The Process Group, a Dallas, Texas-based
consulting company, later created a repeatable procedure for performing Wideband Delphi estimation on software
projects. This guideline explains that procedure.
For more Information, see the Estimating Effort Using the Wide-Band Delphi Technique.
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