Developing and using checklists to improve software effort estimation: A multi-case study

Abstract

Expert judgment based effort estimation techniques are widely used for estimating software effort. In the absence of process support, experts may overlook important factors during estimation, leading to inconsistent estimates. This might cause underestimation, which is a common problem in software projects. This multi-case study aims to improve expert estimation of software development effort. Our goal is two-fold: 1) to propose a process to develop and evolve estimation checklists for agile teams, and 2) to evaluate the usefulness of the checklists in improving expert estimation processes. The use of checklists improved the accuracy of the estimates in two case companies. In particular, the underestimation bias was reduced to a large extent. For the third case, we could not perform a similar analysis, due to the unavailability of historical data. However, when checklist was used in two sprints, the estimates were quite accurate (median Balanced Relative Error (BRE) bias of -0.05). The study participants from the case companies observed several benefits of using the checklists during estimation, such as increased confidence in estimates, improved consistency due to help in recalling relevant factors, more objectivity in the process, improved understanding of the tasks being estimated, and reduced chances of missing tasks.