A system for performing a continuous infusion process using at least two infusion devices (1A, 1B), the system comprising: a first infusion device constituted to deliver a first fluid from a first medication container through a first delivery line at a first flow rate in a first phase, a second infusion device constituted to deliver a second fluid from a second medication container through a second delivery line at a second flow rate in a second phase following the first phase, and a relay device connected to said first delivery line and said second delivery line and constituted to receive the first fluid via the first delivery line in the first phase and the second fluid via the second delivery line in the second phase, wherein the relay device is further constituted to discharge the received first or second fluid (M1, M2) to an outlet delivery line connected to the relay device for administration to a patient, the outlet delivery line having a predefined delivery volume, wherein the system is constituted such that, subsequent to the delivery of the first fluid using the first infusion device in the first phase, the second infusion device in an intermediate phase is operated for a predetermined delivery time to deliver the second fluid at the first flow rate, the predetermined delivery time being determined taking the predefined delivery volume of the outlet delivery line into account, characterized in that the first infusion device and the second infusion device are operative to communicate with each other to transfer information concerning the first flow rate, wherein the second infusion device is operative to determine said predefined delivery time according to the first flow rate and the delivery volume and wherein one infusion device (1A, 1B) knows about the operational status of the other infusion device (1A, 1B). a first infusion device constituted to deliver a first fluid from a first medication container through a first delivery line at a first flow rate in a first phase, a second infusion device constituted to deliver a second fluid from a second medication container through a second delivery line at a second flow rate in a second phase following the first phase, and a relay device connected to said first delivery line and said second delivery line and constituted to receive the first fluid via the first delivery line in the first phase and the second fluid via the second delivery line in the second phase, wherein the relay device is further constituted to discharge the received first or second fluid (M1, M2) to an outlet delivery line connected to the relay device for administration to a patient, the outlet delivery line having a predefined delivery volume, wherein the system is constituted such that, subsequent to the delivery of the first fluid using the first infusion device in the first phase, the second infusion device in an intermediate phase is operated for a predetermined delivery time to deliver the second fluid at the first flow rate, the predetermined delivery time being determined taking the predefined delivery volume of the outlet delivery line into account, characterized in that the first infusion device and the second infusion device are operative to communicate with each other to transfer information concerning the first flow rate, wherein the second infusion device is operative to determine said predefined delivery time according to the first flow rate and the delivery volume and wherein one infusion device (1A, 1B) knows about the operational status of the other infusion device (1A, 1B).