This research studies the effect of descriptive estimate
alterations on the accuracy of the resulting estimate.
The two major reasons for estimate alterations studied
here are the project manager’s experience and
time constraints Estimate alterations done for these
two reasons and their effect on accuracy is also examined.
The confidence of the project manager in the
estimation model and its effect on the accuracy of the
resulting estimate is also studied. The extent of estimate
alterations, estimate alterations made for these
two reasons, and the project manager’s confidence
significantly affect the accuracy of the resulting final
estimate. Finally, the reasons reported by managers to
explain the percentage of relative error in software
effort estimation are documented.