Feed Forward Control Loop

I'll try to describe with an example. You have an electric boiler heating some liquid, you have a means to measure the liquid input flow and temp and you know it's specific heat and the boiler volume and electric power. By using only these input data in a "control loop" you can control the temperature of the exiting liquid i.e predict when to stop applying electrical power without measuring the liquid output temperature. That's feedforwarding. You just ignore output (temp). Measuring it and using that value by e.g. a thermostat, would be a feedback. With open loop this system would be uncontrollable. Hope this (lame) example hasn't made things worse. S.M.