Complex batch processes often suffer a lack of reproducibility from batch to batch due to disturbances such as raw material impurity, variations in start-up initialization and operating conditions. These disturbances and variations have adverse effects on the final product quality but are inherent to the processing and may be difficult for operators to discern. A variety of online process monitoring techniques have been studied in literature for batch processes and have been demonstrated to reliably identify abnormalities, especially when the base case process is well under control.