Discovery of operational spaces from process data for production of multiple grades of products

An industrial case study is presented which uses principal component analys is (PCA) to identify operational spaces and develop operational strategies for manufacturing desired products. Analysis of a historical database of 30 3 data cases from a refinery fluid catalytic cracking process discovered th at the data are projected to four operational zones in the reduced two-dime nsional plane. Three zones were found to correspond to three different prod uct grades, and the fourth is a zone that has a high probability of product off-specification and is very likely caused by product changeover. Variabl e contribution analysis was also conducted to identify the most important v ariables that are responsible for the observed operational spaces, and cons equently strategies were developed for monitoring and operating the process in order to be able to move the operation from producing one product grade to another, with minimum time delays.