Abstract: The invention provides a novel method of monitoring a process. The method also has the ability to take predetermined actions based on the monitored data. These actions avoid or mitigate process abnormalities or upsets that might impact product quality, production, and/or process efficiencies. The method includes the steps of: obtaining at least one input process variable; determining a comparative process value based on the at least one input process variable using a first method having a first time-based weighting function; determining an expected process value based on the at least one input process variable using a second method having a second time-based weighting function; determining a first deviation value based on the at least one input process variable or historical data; calculating a limit range having a maximum limit and a minimum limit using the expected process value and the first deviation value; and comparing the comparative process value to the limit range.