Nearest neighbors methods for root cause analysis of plantwide disturbances

In continuous chemical processes, disturbances travel along propagation paths in the direction of the control path or process flow. This article applies a method based on the nearest neighbors of embedded vectors to historical process data for the purpose of identifying the direction of propagation of disturbances. The resulting measure is sensitive to directionality even in the absence of an observable time delay. Its performance is studied in two industrial case studies, and default settings for the parameters in the algorithm are derived so that it can be applied in a large scale setting.