Optimising the storage assignment and order- picking for the compact drive-in storage system
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One of the most common systems in non-automated warehouses, is drive-in pallet racking with a shared storage policy(which is usually based on the duration-of-stay). Such scheme targets towards an efficient use of storage space, since itsoperation costs are directly related to the size and layout of the warehouse. In this paper, two mathematical programmingmodels and two greedy-randomised based heuristics for finding (nearly) optimal storage and retrieval operation sequencesfor this type of storage system are proposed. The computational effectiveness of the proposed approaches is measured byconsidering two sets of synthetic instances. The obtained results show that the proposed heuristics are not only able tocompute high-quality solutions (as observed when being compared with the optimal solutions attained by the mathematicalprogramming models), but it is also capable of providing solutions in very short running times even for large instances forwhich the mathematical programming model failed to find feasible solutions. At the light of these results, the best heuristicis also tested using a rolling-horizon planning strategy in a real-world case study, obtained from a Chilean company. It turnsout that the attained results are more effective than the company’s current storage policy
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