For the warehouse control unit (WCU), the following activities must be considered:

1. SAP sends a transfer order. Receipt of the order (WMTOID01) must be verified.
2. SAP receives confirmation of the transfer order from the subsystem (WMTCID01)
3. The external system generically blocks an aisle in the warehouse (send WMBIID01)
4. The external system moves a storage unit (send WMSUID01).