The problem of constructing and using the knowledge representation in the process control system is studied. It is shown that when implementing knowledge-intensive business process management, it is necessary to use automated construction and expansion knowledge base to support decision-making in accordance with the current state of the context for the implementation of business process actions. The state of the context is specified as a set of weighted logical facts, the arguments of which are the values of the attributes of the events of the business process log. The sequence of the process implementation at each moment of time is displayed in the form of a probabilistic distribution of the possible rules of executing the actions of the business process in this context. The method of automated construction and updating of the knowledge base of the information system of process control is proposed. The method includes the stages of forming knowledge representation templates, constructing context descriptions, logical facts, constructing rules, and calculating the probability distribution for rules. The method creates opportunities to support decision-making on the management of the business process in the event of a discrepancy between the current implementation of the business process and its model.