Reducing estimation uncertainty with continuous assessment: tracking the "cone of uncertainty"

Abstract

Accurate software cost and schedule estimations are essential especially for large software projects. However, once the required efforts have been estimated, little is done to recalibrate and reduce the uncertainty of the initial estimates. To address this problem, we have developed and used a framework to continuously monitor the software project progress and readjust the estimated effort utilizing the Constructive Cost Model II (COCOMO II) and the Unified CodeCount Tool developed by the University of Southern California (USC). As a software project progresses, we gain more information about the project itself, which can then be used to assess and re-estimate the effort required to complete the project. With more accurate estimations and less uncertainties, the quality and goal of project outcome can be assured within the available resources. The paper thus also provides and analyzes empirical data on how projects evolve within the familiar software "cone of uncertainty".