Strategy: Preferred Unit of Measure Last 
If you use this strategy, the system first proposes quants which do not have the preferred unit of measure (UoM) of the storage type from which you want to pick products. This strategy is important when using stock-specific units of measure (SUoMs).
The system compares the preferred UoM in the product's material master with the alternative UoM of the quants. If these UoMs are not the same, the system proposes the quant first. When you are working with SUoMs, the alternative UoM is set automatically in the quant during goods receipt posting.
Prerequisites
You have defined a stock removal rule in Customizing for Extended Warehouse Management under
Goods Issue Process 
Strategies Specify Stock Removal Rule
. You have specified Preferred Unit Of Measure (sort ascending) as the sort criterion.You have defined a storage type search sequence in Customizing for Extended Warehouse Management under
Goods Issue Process Strategies Specify Storage Type Search
Sequence .You have assigned the storage type search sequence in Customizing for Extended Warehouse Management under
Goods Issue Process Strategies Determine Storage Type
Search Sequence for Stock Removal .You have assigned the stock removal rule to the storage type in Customizing for Extended Warehouse Management under
Master Data Define Storage Type . Alternatively,
you can assign the stock removal rule under Goods Issue Process Strategies Determine Storage Type Search Sequence for Stock Removal .You have specified at least one UoM as being stock-specific for your products in Customizing for Extended Warehouse Management under
Master Data Product Define
Unit of Measure Attributes .You have maintained a preferred UoM in the product material master on the SAP Easy Access screen for Extended Warehouse Management under
Master Data Product
Maintain Product or Master Data Product Maintain Warehouse Product .