Breakbulk and/or Source document Unit of Measure conversion

Hi all,

Considering the following situation:

- Base Unit of Measure for items is pieces
- Other Units of Measure are "Master carton" and "Inner carton". For example: 8 pieces in "inner carton", 32 pieces in "master carton" (which actually is a box with 4 inner cartons)
- Sales orders come from an external system and are always created in pieces
- Inventory is kept in all Units of Measure (pieces, master carton, inner carton) with directed put-away and pick, preferably in the "biggest" Units of Measure, so most of the inventory should be kept in master cartons.

When a sales order (or any other outbound source document) requires 128 pieces, we would like the system to suggest to pick 4 master cartons. But because the source document contains 128 pieces, NAV will first try to pick existing inventory in pieces (driving warehouse employees crazy) while it would be more efficiënt to pick 4 master cartons.

A more complex scenario is when a sales order requires 42 pieces to be picked. In an ideal world the warehouse employee should get a pick instruction for 1 master carton + 1 inner carton + 2 pieces. But again, because the sales line contains pieces, NAV will suggest to first pick pieces (sometimes from multiple locations), then break a master carton into pieces and pick the remaining required quantity in pieces.

We tried to use the "Whse. Change Unit of Measure" function in pickings, but because inventory is held preferably in master cartons, and sales orders always contain pieces, almost every pick line needs to be changed manually.

So the question is: Is it possible, with standard functionality, to automatically let NAV suggest pick lines in multiples of "bigger Units of Measure"? Can this only be accomplished by changing the Unit of Measure on the source documents?