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.