include a drop down for unit of measure on REQ (EA,CS,PCK,BX,LB, etc.) allowing definition by SCS what quantity they are requesting. There then should be a place to define how many units per case and this information should be recorded under the "Supplier parts" tab under the "Parts" section of the system. Once item is received in, you should be able to issue part by unit of measure (EA,CS,PCK,BX) allowing for more accurate inventory and PO receipt relation as well as inventory actual cost on hand information.