A cell controller capable of optimizing the operation of a production system having a plurality of industrial machines operated by an operation program. The cell controller includes: a system operational information analyzer configured to analyze time-series operational information received from the industrial machines via a network, so as to find a part in the system which generates an adverse effect on a cycle time of the entire production system; a state quantity analyzer configured to analyze a state quantity of the industrial machines so as to calculate a degree of margin of motion of each industrial machine; a program modifier configured to automatically modify a velocity or acceleration in the operation program based on the degree of margin; and a simulator configured to execute an operational simulation of the production system in order to confirm a modification result of the operation program.