Unified process monitoring strategy for a facility engaged in the production of multiple portfolio of products

The process monitoring strategies have not kept pace with the development in the production systems. Most of the multivariate statistical process monitoring methods deals with single product portfolio. The current article attempts to devise a unified monitoring strategy for monitoring of multiple products or at least different grades of the same product. A case study from an integrated steel plant producing multiple products has been deliberated to validate the monitoring strategy devised. A comparative evaluation of the unified strategy based on the multigroup variant of principal component analysis (PCA) and the individual strategy based on the conventional PCA was carried out on the basis of three parameters viz. the model fit values, fault detection and the fault diagnosis. In all the three parameters, barring some trifling differences, the unified monitoring strategy seems to replicate the individual strategies well.