One of the most important areas in modern adult education is the transition from lifelong learning to lifelong learning. However, the issues of organizing and conducting training of enterprise personnel are still poorly covered in the literature. The lack of research in this area leads to certain difficulties in the systemic organization of the educational process in enterprises. In this monograph, the issues of construction and management of training of personnel of the enterprise are presented by the author in a complex, taking into account the peculiarities of in-house training. The results obtained are based on a large amount of factual material. The author analyzed the approaches, methods and techniques in building a personnel training system. The model of the in-house training system presented by the author allows developing approaches to personnel training. From the point of view of selection, preparation and training of teachers for in-house training, the developed and presented requirements for the teacher of in-house training are of theoretical and practical importance. Of practical importance are the methodological developments proposed by the author in the applications for the organization of in-house training.