Monitoring Heterogeneous Multivariate Profiles Based on Heterogeneous Graphical Model

Process monitoring using profile data remains an important and challenging problem in various manufacturing industries. Motivated by an application case of motherboard testing processes, we develop a novel modeling and monitoring framework for heterogeneous multivariate profiles. In this framework, a heterogeneous graphical model is constructed to depict the complicated heterogeneous relationship among profile channels. Then monitoring the heterogeneous relationship among profile channels can be reduced to monitoring the graphical networks. Besides, we investigate several theoretical results concerning the accuracy of the estimated graphical structure. Finally, we demonstrate the proposed method through extensive simulations and a real case study.