Achievements and Challenges in Software Resource Estimation

This paper summarizes major achievements and challenges of software resource estimation over the last forty years. We address critical issues that enabled major achievements such as the development of good model forms, criteria for evaluating models, methods for integrating expert judgment and statistical data analysis, and processes for developing new models that cover new software development approaches. Future trends in software development and evolution processes are projected, along with their implications and challenges for future software resource estimation capabilities.