Machine-based modeling of conveyor-type flowshops with application to scheduling and temperature control in slab reheating furnace

This paper proposes a novel modeling scheme for model predictive control of a class of hybrid (continuous/discrete) flowshops, where permutation scheduling of jobs inserted into machines and control of continuous dynamics on jobs inside machines are simultaneously optimized in the conveyor-type flowshops. This modeling allows us to reduce the number of the binary decision variables in the resulting mixed integer programming (MIP) problem, thereby achieving a remarkable decrease in the computational burden of solving it. The proposed method is applied to slab reheating furnace control for a hot strip mill.