The use of experimental design methodology and multivariate analysis to determine critical control points in a process

Abstract The main goal of this article is to present a general framework for looking at an industrial experimental problem—starting from the problem definition stage, utilizing an appropriate experimental design, taking proper response measurements using techniques that describe the desired phenomenon that is to be studied and finally analyzing the data using multivariate techniques. We have focused on three main elements: (1) detect the origin of the different response characteristics in a process, critical control points; (2) relate the response measurements to Near-Infrared spectroscopy (NIRS); and (3) establish relationship between the response measurements taken on the final product and NIR spectra collected for each sample at different sampling points along the process line. The results show the suitability of NIRS not only as a rapid measurement technique for detecting changes in the final product quality at an early stage, but also for process control at the critical control point.