Proactive product quality control: An integrated product and process control approach to MIMO systems

Real-time control of product performance parameters is a key for proactive quality control (QC), as it can prevent the occurrence of potential quality problems in the earliest stage of manufacturing. It is recognized that dynamic product QC must be coordinated with the control of the process through which the product is manufactured. The integrated product and process control (IPPC) design methodology introduced recently is a proven approach to the simultaneous control of both the product quality and the process performance. In this paper, a general IPPC design methodology for multi-input–multi-output (MIMO) systems is introduced. A case study on polymeric coating curing shows that the resulting control system is capable of effectively tracking the set-points of both the product and the process, and demonstrating a satisfactory performance in rejecting disturbances, thereby ensuring achievement of desirable product quality and process performance.