Simplified approach to effort estimation in software maintenance

This article introduces software support and maintenance from effort estimation perspective. Software maintenance is a set of activities needed for cost-effective support of IT solution. More or less, delivery strategies and best practices focus mostly on delivery process and only some of them partially cover effort estimation. Magne J rgensen in his work formulated conclusions that 83 to 84% of all estimation is done by pure expert estimates and estimating models are not used basically due to their complexity. Author introduced his simplified, easy to use approach to effort estimation in software maintenance based on extending PERT formula about quality of estimator and historical experience. Both formulas were verified in sub-competence center for supporting mortgage IS with significantly better result than only pure PERT estimate (98.8% and 91.8% against pure PERT 90.1%).