Evaluation of the effectiveness of the implementation and development of information systems and information technology is one of the challenging tasks in managing it projects. However, we also know that it affect the success of the company, but they also require large investments and carry significant risks. Therefore, the decision to select the automation of business processes should be after in-depth analysis with mathematical tools. The purpose of this work is to show the possibility of expanding the mathematical apparatus of analysis of it projects that require significant investment. The article presents examples of results of expert opinion for estimation of expected cash flows, considering the risks when investing in competing projects, based on the methods of mathematical statistics. Describes the conditions of the solution of a multicriteria problem of choice of one it project of the alternatives, based on economic sense of indicators of risk. The rationale for the use of different methods when comparing projects of different durations (chain of repetition, equivalent annuity, etc.). The introduction of new information systems affects the quality indicators of the business, including improving productivity, reducing errors in performing the tasks, and thereby improving financial results. Selected mathematical methods will allow for different stages of decision-making to provide comprehensive and scientifically-based analysis of project performance and objectivity of the decisions made by the IT-manager
