The part of the stock of an empties article that is assigned to a full product as an empties component is managed under the stock type "tied empties". Stocks of empties that are not assigned to any full product are managed under the stock type "unrestricted-use". Stock of tied empties are managed at site level, but not at storage location level.

Since tied empties are managed as a separate stock type, you can always see at a glance how much of your empties are tied to a full product and how much is unrestricted. You can also carry out a physical inventory for the unrestricted-use empties stock, without having to count the stock of tied empties.

You use movement type 441 to transfer empties stock from stock type "unrestricted-use" to stock type "tied empties". Movement type 442 reverses the transaction.

There are 15 crates of the full product "beer 1" in stock, and 20 crates of the full product "beer 2" in stock. Both have an identical bill of material for empties for the unit of measure "crate" (24 bottles and a crate).

Thus, the "bottles" and "crate" part of the empties components are tied empties stock. There is also a part of the empties stock which is unrestricted.