A method for grouping a plurality of orders in an order queue of a warehouse management system, each order including one or more items and each item being associated with a physical location in a warehouse. The method includes determining a physical location in the warehouse of each item in the plurality of orders. For each order, the method also includes establishing at least one cluster region, each cluster region including at least one item from the respective order. The method further includes grouping the plurality of orders based on the physical locations of the cluster regions in the warehouse to form at least one order set.