Abstract: A process control system for controlling a process including a plurality of sub-processes, the process control system including a plurality of control modules each associated with one of the plurality of sub-processes. At least one of the plurality of control modules includes a model, a communicator, and a controller. The model includes a sub-process model defining a relationship between variables of the associated sub-process, and an inter-sub-process model defining a relationship between a variable of another sub-process and at least one of the variables of the associated sub-process. The communicator communicates with control module associated with the another sub-process to determine an updated value for the variable of the another sub-process. The controller uses the model and the updated value to determine a control signal for adjusting a manipulated variable of the associated sub-process. The process control method is also provided that is performed by the process control system.