We address an integrated scheduling problem of machines and cranes for a steel making process. Jobs go through three production stages, each of which has multiple machines, and cranes transport jobs between two consecutive stages. There are multiple cranes, and each crane can handle one job at a time. We propose a novel mixed integer programming model for this integrated scheduling problem by considering the crane interference for the first time. We then develop an efficient heuristic algorithm to provide a near optimal solution in a short time.