Statistical Process Control (SPC) and Automatic Process Control (APC). Statistical Process Control as developed by Shewhart and Deming is being used internationally as a method for continuous improvement and cost reduction. SPC is applied to manufacturing and service industries, and is now being used more and more in Germany. In the chemical industry many processes are equipped with automatic control or advanced control strategies. This article outlines how SPC and APC supplement each other. The first part describes APC methods as a means of achieving constant quality. The second part describes SPC in its original form as a method for continuous quality improvement. After the comparison of SPC and APC an example is presented : automatic rectifying column. The combined application of SPC and APC leds to synergistic results which would have been hard to achieve otherwise.