The article is devoted to the issues of estimating the duration of software development, the solution of which can significantly improve the efficiency of software projects. The relevance of the topic is conditioned by the rapid development of software development methodologies, on which the existing algorithms of such estimation depend, and, as a consequence, by the rapid obsolescence of approaches to solving this problem. A systematic analysis of the main algorithms for estimating software development duration is carried out. The classification of such algorithms is presented. The algorithm of software development duration estimation and the idea of the system implementing it, which will allow end users to automate this process, are proposed. The approaches to implementation of algorithms of retrospective (historical) estimation, PERT, expert estimation are considered. The prospectivity of researches in the field of implementation of methods of expert evaluation using neural networks is shown. The architecture of the proposed system is described. A prototype of the system implementing the method of retrospective evaluation based on the evaluation of the speed of the development team is developed.