A method for assigning surplus slabs in slab yards to orders includes loading slab pre-yards of a plurality of production lines with surplus slabs, describing the assignment of the surplus slabs to the orders with a mathematical model, grouping order data and slab data based on steel grades, obtaining an assignment scheme for the surplus slabs and the orders in each group with a mixed scatter search algorithm, and assigning the surplus slabs to the orders using the assignment scheme. If a surplus slab is in a pre-yard of a production line associated with an order the surplus slab is assigned to, the slab is moved using a crane to the production line. Otherwise, the slab is moved to the pre-yard associated with the production line, and then moved using a crane to the production line. The slab is then heated and rolled by the production line.
