Performance issue with Inventory Reservation API

Summary:

We are experiencing a performance issue with the Inventory Reservation API. The customer has approximately 5,000 order lines and each line is reserved one by one using fscmRestApi/resources/11.13.18.05/InventoryReservations API, and the inventory reservation process is taking nearly one hour to complete.

Customer is expecting each line inventory reservation is expected to be completed in less than 100 ms

The customer is not using the standard orchestration flow. Instead, they have implemented a custom orchestration flow that skips the standard Inventory Reservation step.

The reason for this customization is that they want the reservation to occur only if the entire order can be reserved. In their middleware, they first validate on-hand inventory availability for the complete order. If sufficient inventory is available for all lines, they then invoke the Inventory Reservation API to reserve the order lines individually, one line at a time.