Abstract: An efficient computer implemented method is used to design slabs for production from an order book. This method minimizes the number of slabs designed to fulfill an order book. This method is based on a heuristic algorithm which is a variant of the greedy approach for the set covering method. The variations are novel in three ways. First, designing slabs using the flexibility in the order size; second, using weight for choosing large slabs; and third, controlling the exponential nature of enumeration of the set of all subsets by constructing only the largest slab at each step.

Abstract: A fast computer implemented method generates near-optimal solutions to the multi-objective inventory matching problem by solving for multiple objectives simultaneously and generating multiple non-dominating solutions. The method implements a multi-assignment backjumping algorithm that consists of three steps. The first step is a rappeling step in which a feasible solution is created by applying Iterative Bipartite Matching and maximum flow algorithm. Near-optimal feasible solutions are stored in a non dominated set. The second step is to use a multi-key sort to identify undesirable matches in a given feasible solution. The third step is backlifting the solution by removing undesirable matches from the feasible solution and places those undesirable matches on a no good set of matches. If the feasible solution is non-dominated, a copy is stored in a non-dominated set. The feasible solution is finally provided as input to the repelling step.

Abstract: A scheduling method suitable for use in a primary steel production area operating in either direct rolling or direct hot charge rolling modes, collectively referred to as synchronized rolling. The steel production area comprising a continuous caster, for input of slabs to a hot strip mill. An order load for some finite period (e.g. one week) is received as input to the method. The method generates a caster schedule and a hot strip mill schedule which fills the order load with the objective of operating the continuous caster and the hot strip mill with minimal interruption. The generated schedule works within the constraints imposed by both the continuous caster and the hot strip mill. The schedule generation process also considers key operating constraints of individual facilities as well as those on which the facility has dependencies. The schedule also addresses objectives such as maximizing throughput, maximizing on-time delivery, and minimizing operating costs.