Performance assessment in order picking systems: a visual double cross-analysis

The aim of this paper is to introduce a practice-ready systematic methodology for the management of storage assignments and allocation decisions as well as an assessment of the resulting performance in an order picking system (OPS). Built on extant and well-known metrics of performance this method implements a double cross-analysis through an original visual tool that is easy to understand by warehousing managers and practitioners. This tool is organized in two main steps. The first step is a cross-analysis that combines multiple performance indicators to help the decision-maker understand whether an OPS provides the scope for performance improvement. A comparison with potential storage configurations is then conducted in the second step through a tailored multi-scenario cross-analysis, which attempts to identify the best combination of allocation and assignment policies capable of minimizing the overall traveling performance. The proposed methodology is applied to a significant real-world OPS. The selected case study represents a reference framework for decision-makers and practitioners.