Return on Software: Maximizing the Return on Your Software Investment

Estimating by Multiple Methods

An organization with good estimation techniques doesn't depend on one single estimation method. The sophisticated organization uses several estimation methods throughout the project. There are two reasons for using different methods. One reason is that the different methods will be used to “sanity check” the others, as described above. The other reason is that the preferred method can change over the life of the project; different methods typically perform better in the different phases of a project. Both of these reasons are described here in more detail.

We already talked earlier about how expert judgment can be used to “sanity check” estimates arrived at by the other methods. This same idea can be generalized: ...