2020 Volume 33 Issue 9 Pages 259-265
In the steel industry, the role of the slab yard which is the intermediate process between the steelmaking and the rolling is becoming significant. By promoting the logistics from steelmaking to rolling, we can reduce the cost of fuel to reheating and improve the productivity. In the yard slabs are expected to be sorted into piles as little transport as possible and as high as possible. It is the slab stacking problem (SSP). In the previous paper, we formulated SSP with the 0-1 programming. It turned out that this formulation gets lack of memory with large scale problem. For settling this problem, in this paper, we apply the column generation method to SSP. But, since SSP is 0-1 integer problem, the optimal error remains. So we developed the method of local search for the neighborhood of the generating columns using the dual optimal solution to obtain the exact solution. Finally, we show the effectiveness of this method with the computational experiment using the real operational data.
