Industrial warehouses are typically composed by multi levels scaffolds holding pallets, each pallet carrying one or more manufacturing item. The paper introduces the problem of the wasted space in industrial warehouses and describes the algorithms implemented in a simulation software able to suggest how to organize the storage of the manufacturing items. The proposed software uses effective and efficient search algorithms to minimize the overall storage lost space. The general structure of the numeric platform and the logics of the solver algorithms are described together with the strategies adopted to reduce the computation time. Typical results obtained in an industrial environment working in the plastics sector are presented and discussed.