CONTROLLER FOR PLANT

PROBLEM TO BE SOLVED: To automatically operate operating procedures among operation variables where influences become minimum by considering interaction among the operation variables caused by a time factor of processes of a plant.SOLUTION: The controller for a plant includes a control logic database for storing operation variables to use for a plurality of logic operations, a control signal generation part for performing logic operation and generating a plurality of control signals to be given to the plant, and an operating procedure operation part for operating the operating procedures of operation variables. The operating procedure operation part obtains a delay time in logic operation before a result of logic operation of the first operation variable and a second operation variable are added with respect to operation variables associated with one another among a plurality of operation variables every operation variable and decides operating procedures of the plurality of operation variables. When it changes value of operation variables to use in the plurality of logic operation, the control signal generation part follows changed order of other operation variables associated with the operation variable according to operating procedures of the plurality of operation variables obtained by the operating procedure operation part.