When the dynamic model had been completed, the response of the system was then measured for 10 % steps in each of the input variables. A sampling time of 1 minute was used, as this is the smallest time interval possible from the SCADA system ,and it has proven adequate for obtaining all of the process dynamics from this system. The overall juice residence time in the multiple effect is about 45 minutes, and thus the settling time to steady state was set at two hours. The convolution model is made up of the step response coefficients, i.e. the change in syrup brix from steady state at each time interval following the step change. By combining the responses to steps in each of these inputs, and assuming linearly and time invariance, a dynamic matrix is formed, which predicts the future output of the system based on present and past inputs