Within SAP Inventory Management, there are two methods how stock are moved between plants using a 2-step process:
Stock Transport Orders (UB)
Transfer Posting
What does 2-step mean?
Example: Lets assume stock is moving from Plant A (Storage Location 0001) to Plant B (storage location 0002).
Two step means that two transactions will be used to move the stock. After the first transaction, stock has left plant A but it is not yet available at Plant B. Only after the second transaction is it available for use in Plant B.
Some reasons for using 2-step movements (and not 1 step):
Long time span between leaving Plant A and arriving at Plant B
Need to control when goods leave plant A but not received at plant B
Using Stock Transport Orders (STO)
Steps:
Create a Stock Transport Order (ME21N, Purchase Order doc type UB)
Process Goods Issue against STO (MIGO > Goods Issue > PO) – movement type 351
Process Goods Receipt against STO (MIGO > Goods Receipt > PO) – movement type 101
The use of Planned Orders and Purchase Requisitions are optional.
Using Transfer Postings (TP)
Steps:
Process a Transfer Posting (MIGO > Transfer Posting) - movement type 303
Process a Transfer Posting (MIGO > Transfer Posting) - movement type 305
The Transfer Posting can be done with reference to a Reservation. Although this is not used a lot.
Similarities between Stock Transport Orders (STO) and Transfer Postings (TP)
Both use transaction MIGO for both steps
After first step, goods are already reflected in receiving plant and not available
Differences between Stock Transport Orders (STO) and Transfer Postings (TP)
Movement types are different
351 & 101 for STO
303 & 305 for TP
Stock types at receiving plants are different
- In Transfer (MARC-UMLMC) for TP
- Stock in Transit (MARC-TRAME)for STO
For STO, 351 and 101 is group together where for TP there is no link between 303 and 305
STO requires more transactions than TP
STO must be configured for the sending plant / receiving plant where no plant specific configuration exists for TP
STO is based on Stock Transport Order (type of Purchase Order). Where no purchasing document is used for TP
STO can be initiated with a Planned Order or Purchase Requisition
Planning (MRP) can be used to initiate movements, but only STO's
Configuration required to use STO
Config: MM > Purchasing > Purchase Order > Set up Stock Transport Order > Assign Document Type, One-Step Procedure, Underdelivery Tolerance
Here the source plant, destination plant and allowed STO document type is specified.
