Reserving Item Inventory across multiple nodes in Sterling Order Management

Answer

It is possible that one item can be reserved across multiple nodes by passing reservation id at order line level (OrderLine/@ReservationID). However system doesn't use the reservation, it instead creates an OPEN_ORDER demand.

The only way to achieve the above is to split the order lines based on how much is reserved at which node. But splitting lines may not be a good solution.

Without the shipnode at the order line level the order would be created as OPEN_ORDER.

From createOrder API java docs:
For Reservation, If a ShipNode is passed and either:

• ReserveInventoryFlag value is Y
  
• The Rule RESERVE_INVENTORY is set to Y
  
• ReservationID is passed
  
• Reservation is mandatory for the order line,

A supply update is made at ShipNode with the supply type configured in ProcurementPlacedSupplyType attribute in document params. This supply compensates for the extra demand update made. When the order is scheduled and procurement order is created, the extra supply as well as demand updates are removed. As much of the requested quantity as is available is created with a Status of 1050 - DraftOrderReserved or 1200 - Reserved, based upon whether the order is Draft Order or not. The remaining quantity in created with a status of 1000 - DraftOrderCreated or 1100 - Created.
If reservation cannot be performed for a line as specified above, a new line will not be created if the rule RESERVATION_MANDATORY is set to Y or the order line level flag RESERVATION_MANDATORY which overrides the rule has a value Y. In such a case, the lines which are not created will be present in the createOrder api output under the UnprocessedLines node. The UnprocessedLines is not template controlled and will always be given in the api output whenever a line could not be created due to reservation failure. If the ReservationID is passed, create order will try to reserve inventory by first checking existing reservations for the segment (ReservationID passed), and if not available then check in the general pool (available non reserved inventory). A findInventory api call is made to find Inventory from the general availability pool.
When looking up inventory availability for doing reservations, supplies and demands of the item/node combinations that are being marked as having incorrect inventory picture will not be considered.
Hence passing the shipnode at the order line level is mandatory along with other parameters that are passed at the order line reservations element.