An infusion system, comprising: a first delivery unit configured to deliver a first infusate to an infusion circuit; a measurement device configured to determine an amount of undelivered first infusate remaining to be infused; and a control system configured to: control delivery of the first infusate from the first delivery unit; enable input of a predetermined volume of the first infusate to be delivered and input of a predetermined time period for infusion of the predetermined first infusate volume; and determine a time remaining in the predetermined infusion time period; the infusion system being characterized in that the infusion system further comprises: a second delivery unit configured to deliver a second infusate to the infusion circuit; and wherein the control system is further configured to: control delivery of the second infusate from the second delivery unit at a predetermined dilution flow rate; stop and restart both of the first and second delivery units simultaneously; communicate with the first delivery unit, the second delivery unit, and the measurement device to determine a first infusate infusion flow rate based on the predetermined first infusate volume, the predetermined infusion time period, the determined amount of undelivered first infusate remaining in the system and the determined time remaining in the predetermined infusion time period; recalculate the first infusate infusion flow rate after any interruptions of either the first or the second pump units; and control the first delivery unit to deliver the first infusate at the determined first infusate infusion flow rate. a first delivery unit configured to deliver a first infusate to an infusion circuit; a measurement device configured to determine an amount of undelivered first infusate remaining to be infused; and a control system configured to: control delivery of the first infusate from the first delivery unit; enable input of a predetermined volume of the first infusate to be delivered and input of a predetermined time period for infusion of the predetermined first infusate volume; and determine a time remaining in the predetermined infusion time period; control delivery of the first infusate from the first delivery unit; enable input of a predetermined volume of the first infusate to be delivered and input of a predetermined time period for infusion of the predetermined first infusate volume; and determine a time remaining in the predetermined infusion time period; the infusion system being characterized in that the infusion system further comprises: a second delivery unit configured to deliver a second infusate to the infusion circuit; and wherein the control system is further configured to: control delivery of the second infusate from the second delivery unit at a predetermined dilution flow rate; stop and restart both of the first and second delivery units simultaneously; communicate with the first delivery unit, the second delivery unit, and the measurement device to determine a first infusate infusion flow rate based on the predetermined first infusate volume, the predetermined infusion time period, the determined amount of undelivered first infusate remaining in the system and the determined time remaining in the predetermined infusion time period; recalculate the first infusate infusion flow rate after any interruptions of either the first or the second pump units; and control the first delivery unit to deliver the first infusate at the determined first infusate infusion flow rate. a second delivery unit configured to deliver a second infusate to the infusion circuit; and wherein the control system is further configured to: control delivery of the second infusate from the second delivery unit at a predetermined dilution flow rate; stop and restart both of the first and second delivery units simultaneously; communicate with the first delivery unit, the second delivery unit, and the measurement device to determine a first infusate infusion flow rate based on the predetermined first infusate volume, the predetermined infusion time period, the determined amount of undelivered first infusate remaining in the system and the determined time remaining in the predetermined infusion time period; recalculate the first infusate infusion flow rate after any interruptions of either the first or the second pump units; and control the first delivery unit to deliver the first infusate at the determined first infusate infusion flow rate. control delivery of the second infusate from the second delivery unit at a predetermined dilution flow rate; stop and restart both of the first and second delivery units simultaneously; communicate with the first delivery unit, the second delivery unit, and the measurement device to determine a first infusate infusion flow rate based on the predetermined first infusate volume, the predetermined infusion time period, the determined amount of undelivered first infusate remaining in the system and the determined time remaining in the predetermined infusion time period; recalculate the first infusate infusion flow rate after any interruptions of either the first or the second pump units; and control the first delivery unit to deliver the first infusate at the determined first infusate infusion flow rate.