The book "Technical and economic substantiation of engineering solutions in diploma projects on reliability, repair and operation of machines" by Novikov Alexander Nikolaevich, Batishchev A. N. and Kuznetsova Yu . A. is a unique educational material that will become an indispensable assistant for students of engineering specialties and practicing specialists in the field of mechanical engineering . This work is not just a textbook, but a whole guide to the complex world of feasibility studies, which helps readers understand the intricacies of the design and operation of machines. The book covers a wide range of topics related to the reliability, repair and operation of machines, which makes it relevant for both students and professionals seeking to deepen their knowledge in this field. The authors offer readers a detailed understanding of how to justify engineering solutions, taking into account not only technical but also economic aspects. This is especially important in today’s market, where efficiency and profitability play a key role. Readers interested in the topics of reliability and repair of machines will find in the book many useful recommendations and practical examples. It will be useful for both undergraduate and graduate students, as well as for engineers working in the design and operation of machines. The book will become a reliable assistant for those who want to learn how to properly justify their decisions and make informed decisions in the process of developing diploma projects. The topics raised in the book include not only theoretical aspects, but also practical recommendations for conducting technical and economic analysis. The authors emphasize the importance of an integrated approach to design, which takes into account all possible risks and costs. This allows the reader not only to learn to justify their decisions, but also to develop critical thinking, which is an important skill for any engineer. The style of the authors is distinguished by clarity and accessibility of presentation, which makes the material understandable even for those who are just starting their way in engineering. Novikov, Batishchev and Kuznetsov use many examples from real practice, which helps the reader to see how theoretical knowledge is applied in life. This makes the book not only a tutorial, but also a practical guide that can be used at every stage of the design process. In addition, this publication can be useful for teachers who are looking for quality materials for the preparation of their students. The book offers many ideas for discussion in seminars and lectures, which contributes to a deeper understanding of the topic. If you are looking for literature that will help you master the feasibility study in engineering projects, then the "Technological and economic justification of engineering solutions in graduate projects for the reliability, repair and operation of machines" will be a real find for you. This is not just a book, but a whole world of knowledge that will open up new horizons in the field of mechanical engineering and help you become a successful specialist. Do not miss the opportunity to deepen your knowledge and skills with this wonderful tutorial!