This work is devoted to the study of the principles and approaches to evaluating the efficiency of business processes carried out by the well workover department of an oil-producing enterprise. According to statistics, service production is a major source of enterprise costs. It accounts for 30-50% of all operating costs. Due to the fact that the majority of large oil fields in Russia are at the final stage of development (more than 70%), the largest share in the composition of operating costs is services for well workover. Accordingly, the purpose of the study was to substantiate the theoretical provisions for managing the efficiency of business processes in the well workover of an oil-producing enterprise and to develop practical recommendations for their implementation. The paper focuses on the main approaches to assessing the efficiency of enterprises as well as the problems that arise when solving problems with the presented approaches due to their inconsistency with new economic challenges. The introduction of changes accompanying the transformation of such approaches made it possible to develop a new management system based on the implementation of the principles of improving the efficiency of business processes in well workover. This, in turn, led to the development of a methodology for a comprehensive assessment of the efficiency of business processes being implemented, which makes it possible to integrate with the concept of managing the efficiency of an oil-producing enterprise.