Reservation hierarchies, in Warehouse management > Setup > Inventories, is a mandatory setup in warehouse management. Reservation hierarchies define the sequence of reservations and dictate which items will be reserved based on priorities, such as storage and tracking dimensions.
For example, with batch items, typically the earliest dates of expiration are reserved first in the respective storage dimension from which they are being issued.
The Site, Warehouse, Inventory status, Location, and License plate dimensions are all required levels in a reservation hierarchy. Additional dimensions such as Batch number and Serial number only need to be included if they are used in the associated tracking dimension group.
The elements in a reservation hierarchy determine which dimensions must be recognized when the actual reservation occurs. Each dimension is required for the reservation, and the order of the elements in the hierarchy is important when you make the reservation. However, you do not always have to provide all dimensions in the hierarchy when placing an order because the reservation system can identify and provide dimensions that are missing in the required sequence of the hierarchy.
The location of an item is identified by the warehouse management system. If you want to make a dimension that is below a location that is required for the ordering process, this dimension must be moved above the location in the hierarchy.
For example, if you want to reserve an item with a specific inventory status, you can specify Site, Warehouse, and Inventory status dimensions. A reservation cannot be based on only Site and Inventory status dimensions because items with the same inventory status might be in different warehouses on a site. The warehouse ranks higher in the hierarchy than inventory status. However, the site and the inventory status that you specify will be enough information for the reservation system to determine a warehouse that has the items on hand.
If you have a product that customers usually order from the same batch number, then the batch number should be determined when the order is entered. In this case, the Batch number dimension must be listed above the Location dimension in the reservation hierarchy.
To assign a reservation hierarchy to a released product, a storage dimension group and a tracking dimension group must be assigned to the product. Also, the physical tracking and storage dimensions that are listed for the product in the Storage dimension groups and Tracking dimension groups fields must correspond to the dimension fields in the reservation hierarchy. The dimension fields in the reservation hierarchy are listed on the Inventory reservation hierarchy page.
If an item has no transactions, you can change the reservation hierarchy for the item. However, if an item has transactions, you must go through a separate process to change the reservation hierarchy.
Flexible reservation for batch tracked items
When using WMS enabled operations, this inventory strategy allows flexibility in the inventory reservation policy to allow businesses who sell batch tracked products to register their customers' request for specific batches on sales orders. Reservations associated with the "Batch-below[location]" inventory reservation hierarchy postpone the picking until warehouse picking operations start, not when the customer order is placed.
When selecting the Allow reservation on demand order for Batch number on the Inventory reservation hierarchy form, all of the dimensions will be checked (by default all dimensions above location are checked), and the dimensions between batch number and location are automatically reserved after you reserve a specific batch number on the order line.
The following set of rules is valid when quantities are processed, and a batch number is committed to a specific order:
To allow reservation of a specific batch number for an item under the "Batch-below[location]" reservation policy, the system must reserve all dimensions up through location. This range typically includes the license plate dimension.
Location directives aren't used when picking work is created for a sales line that uses order-committed batch reservation.
During warehouse processing of work for order-committed batches, neither the user nor the system is allowed to change the batch number. (This processing includes exception handling.)
When setting up items in Supply Chain Management, and you are not using warehouse management, the system requires that you use the following five fields for the item:
- Item group
- Item model group
- Storage dimension
- Tracking dimension
- Sales unit (of measure)
When the item's storage dimension is assigned to a storage dimension that uses warehouse management, several more fields become required:
- Reservation hierarchy
- Unit sequence group
- Unit conversions (if the Unit sequence group includes multiple units of measure)
- Filters (if required by the Item group)