1. A method of optimizing a complex manufacturing process performed on a subject to achieve a plurality of processing objectives, the method comprising the steps of: providing a system comprising a graphical user interface, a process module in communication with the graphical user interface, and an optimization module in communication with the process module, the process module comprising a training module, an empirical relationships database, an analytical equations database, a heuristic knowledge database, and a process models database, the optimization module comprising an optimization engine, the system controlling an apparatus adapted to perform a grinding operation; using the graphical user interface to input into the system at least one processing variable and constraints for the plurality of processing objectives of the grinding operation, the at least one processing variable comprising at least one parameter of the grinding operation, operating parameters of the apparatus for performing the grinding operation, and material of the subject, the plurality of processing objectives comprising at least one of cost of the grinding operation, cycle time of the grinding operation, and at least one desired property of the subject following the grinding operation, the at least one desired property comprising at least one of surface roughness, residual stress, and out-of-roundness of the subject; operating the apparatus to perform a trial of the grinding operation on a specimen of the subject using the at least one processing variable; inputting the at least one processing variable used in the trial and empirical data from the trial into the training module, the training module generating at least one empirical relationship between the at least one processing variable used in the trial and the empirical data from the trial and storing the at least one empirical relationship in the empirical relationships database; using the process module to generate a process model that takes into consideration heuristic knowledge of the grinding operation stored in the heuristic knowledge database, the at least one empirical relationship stored in the empirical relationships database, and optionally analytical equations stored in the analytical equations database and relating to the grinding operation; storing the process model in the process models database; and operating the optimization module by which the process model is employed to optimize the grinding operation by adjusting the at least one processing variable and inputting the adjusted processing variable into the apparatus before again operating the apparatus to perform the grinding operation and achieve the plurality of processing objectives.