Warehouse reshuffling: Insights and optimization

• Quantifies and compares the impact of different operational assumptions.
• Develops the first mathematical model formulation of the general warehouse reshuffling problem.
• Develops heuristic solutions that work well for large practical problem instances.
• Proves when minimizing reshuffling moves does not necessarily minimize reshuffling distance.

Warehouse reshuffling is a reorganization strategy that consists of repositioning items by moving them sequentially. This study investigates how to optimize warehouse reshuffling and quantifies the effect of common assumptions. A mathematical programming formulation for the general warehouse reshuffling problem, the complexity of the problem, several heuristics based on the problem structure, a formal proof delimitating instances where double-handling can be a productive move, and managerial insights on the performance of reshuffling policies in various environments are presented. Experimental results suggest that the proposed heuristics improve upon a benchmark heuristic by relaxing how cycles are handled and incorporating double-handling.