Stacking and Transporting Steel Slabs using High-capacity Vehicles

A crucial task of steel plant logistics is the transportation and intermediate storage of semi-finished casting products, so-called steel slabs. We consider a fleet that consists of high-capacity vehicles. The vehicles are used to transport steel slabs within the steel plant, i.e., between facilities and distinct areas of the slab yard, and they can carry out stacking operations autonomously. The slab yard stores a majority of all steel slabs. It is organized in rows that function as a two-dimensional stacking area. Each row consists of multiple stacks built up by steel slabs that are located on top of each other. Retrieving steel slabs from stacks amounts to solving an extended block relocation problem (BRP). We study a combined approach for solving both the routing of steels slabs within the plant and the stacking of steel slabs in storage as part of their retrieval during a vehicle’s pickup operation.