Methods and systems for controlling one or more pumps of a heart-lung-machine. An illustrative method may comprise receiving an actual flow rate of a pump, determining the actual flow rate is from a primary pump, determining an available amount of the actual flow rate of the primary pump that is available to one or more subordinate pumps, comparing the available amount of the actual flow rate of the primary pump to a sum of set flow rates of the one or more subordinate pumps, and operating the one or more subordinate pumps in a proactive control mode or a reactive control mode.