Efficiency is improved by grouping the orders, since the detail allocations are examined and, if necessary, the allocations rationalized. There is no direct link between orders in a bulk pick, other than the fact that they have items in common and can thus be grouped together.

Bulk pick is similar to batch pick in that multiple orders are picked concurrently, the difference is bulk pick orders require sorting or a secondary pick at a subsequent stop. This typically results in more space requirements.