SAP Determining the Picking Location
The sales goods must be picked from a particular storage location when delivery note is created. The goods are also issued from the storage location that is specified in the delivery. If picking activity is carried out using the warehouse management, the storage location in the delivery note determines which warehouse is responsible for picking.
Delivery item category determines whether the item is relevant to picking activity. For example, text items are not relevant for picking and you do not need to specify a storage location. Check box ‘Relevant for pick’ controls whether the item category is relevant for picking.

Picking storage location is not available in the sales order, because the person responsible for processing sales order do not have enough information to specify the storage location. When the delivery is created, there are general two methods to determine the picking storage location.