The surgical treatment protocols recommended by professional communities today do not include indicators of the duration of the operation stages and inter-stage intervals, although they are necessary for improving staff coordination and reducing errors, thereby enhancing the safety and effectiveness of surgical treatment. The purpose of the study is to compare the duration of operations, operational stages and inter-stage intervals performed by one surgeon (as well as by different ones) during homogeneous and different operations to determine possible standards and estimates of time losses for preparatory stages (inter-stage intervals). The duration of cardiac surgery stages was surveyed during monitoring and computer observation of 3,832 patients. The results show that the indicators of average duration of the stages can be used as guidelines when drawing up protocols of operations, provided that the operation was successful and the perioperative period was free of complications. Protocols for the treatment of the cardiovascular system diseases, both surgical and therapeutic, should take into account the time spent on the stages and procedures of treatment. This will improve quality assessments and prognostic capabilities both for individual stages and for operations in general.