The article is devoted to the key aspects of effective financial modeling using the Project Expert program, which is designed to analyze investment projects. In an ever-changing economic environment, proper financial planning is becoming critical to business success. The article begins with a discussion of the fundamentals of financial modeling, including the collection and preparation of data necessary to create an accurate model. Further attention is paid to the functionality of Project Expert, which allows users to easily enter data, set formulas, and perform calculations. Special attention is paid to various methods of analysis, such as scenario analysis, which allows you to assess the impact of various factors on the financial results of the project. Examples of optimistic and pessimistic scenarios are considered, as well as risk analysis, which makes it possible to identify potential threats and develop strategies to minimize them. In addition, the article highlights the importance of data visualization, which helps to make the analysis results more understandable and accessible to stakeholders. In conclusion, methods for monitoring and updating the financial model based on evidence are discussed, which contributes to a more accurate assessment of the effectiveness of the project.