A method of controlling flatness of a strip of rolled material in a production line including a hot rolling mill and at least one cold rolling mill, downstream of the hot rolling mill, the method including determining flatness data of the strip in one or more of the at least one cold rolling mill and/or following passing of the strip through one or more of the at least one cold rolling mill; determining a thickness profile target of the strip for the hot rolling mill based on the flatness data; and passing the strip through the hot rolling mill and adjusting the thickness of the strip based on the thickness profile target. A control system and a production line are also provided.