Montocchio and Scott (1985) reported good results using a variation on a PID based throughput control scheme, which was installed at amatikulu sugar mill. By changing the configuration of the evaporator effects, and using good variable pairings, the evaporator system was made less sensitive to disturbances. This robustness was dependent on tight juice flow control, and a well designed station, which was nearly always run at full throughput. This scenario cannot be assured in plants where flow delays due to lack cane are common.