A rolling mill system uses a number of autonomous control units, each associated with one piece of equipment of the rolling mill system. The autonomious control units include data indicating not only their constraints of operation, but also reflecting the constraints of operation of machines to which they are attached and with which they share common operating parameters. An autonomous control unit associated with a machine having operating parameters in common with another machine of the rolling mill system adopts the intersection of the ranges of the machine constraints of the two machines. Machine constraints are preserved to the extent possible as ranges, so as to permit flexibility in selecting and seeking goals by the individual autonomous control units.