When a picking list is generated, it is added to the Picking list journal. If an applicable document flow with direction 'Outbound' and type 'Picking' exists, also a record is added to the Outbound message queue. When this record is processed, the 'Warehouse - Picking list to XML' message is run. As a result, an EDI picking list message file is created and sent to the 3PL warehouse to inform them on what must be picked.
To generate a picking list, on a Sales orders page, on the Action pane, on the Pick and pack tab, in the Generate group, click Picking list.
For more information on picking lists, refer to Outbound process.