1. A method of controlling a process in a semiconductor manufacturing system, comprising: setting process control input data for said process in said semiconductor manufacturing system; measuring process control output data from said process in said semiconductor manufacturing system; determining a relationship between said process control output data and said process control input data; setting target process control output data to a target result of the process; and calculating new process control input data by minimizing a difference between said target process control output data and predicted process control output data, wherein said predicted process control output data is determined using said relationship applied to said new process control input data.