article describes a formal approach to making managerial decisions based on precedents and building case management systems. Speaking of a precedent without reference to a specific subject area, it is important to emphasize that we are talking about a retrospective restoration of certain events, gaining experience, and possibly making managerial decisions similar to those that have been observed in the past. Decision making in human-technical systems is fraught with significant difficulties. These difficulties arise both as a result of uncertainty and the lack of experience in the functioning of systems (decision making) in new (changing) conditions. As practice shows, many real complex socio-technical systems operate in one day mode (short-term planning and manual control), without relying on previous experience, which ultimately leads to the need to use manual control in case of any emergency situations. It has been emphasized that in any socio-technical system that depends on the human factor, a knowledge-based management system is necessary, which, on the one hand, allows formalizing the decision-making process as a whole, and, on the other hand, reduces the dependence on the knowledge of individual narrow specialists in the subject area. To a certain extent, such systems accumulate knowledge; nevertheless, it is obvious that there are certain prerequisites (including external ones) under which this knowledge can be effectively applied. Often knowledge alone is not enough, experience is also needed. There have been considered the precedent decision-making systems based on the factor-domain principle of the subject area classification.