Abstract. Order picking is the most labour-intensive and costly activity of warehouses. The main challenges of its improvement are the synchronisation of warehouse layout, storage assignment policy, routing, zoning, and batching. Furthermore, the competitiveness of the warehouse depends on how it adapts to the unique customer demands and product parameters and the changes. The operators usually have to manage the picking sequence based on best practices taking into consideration the product stacking factors and minimising the lead time. It is usually necessary to support the operators by making effective decisions. Researchers of the pallet loading problem, bin packing problem, and order picking optimisation provide a wide horizon of solutions but their results are rarely synchronised.
Necessity and complexity of OPRO based on PLF
163The research defines the order picking routing problem based on Pallet Loading Feature (PLF). It describes measurement and product stacking rule evaluation methods to highlight when the PLF based optimisation is necessary. The paper shows that in order picking problems based on PLF, the number of combinations a brute-force search algorithm has to examine grows exponentially, which highlights the importance of meta-heuristic optimisation. The study describes a Simulated Annealing algorithm for order picking based on PLF.