The following three conditions must exist together for high inventory lock contention:
If the transaction volume is low and only one transaction is running, this transaction does not experience any inventory lock contention. The likelihood of inventory lock contention grows as the number of concurrently running inventory processing transactions (e.g., createOrder, schedule, release, and so forth) increases.
The impact of lock contention may be minimal if the lock-holding times are very short. Blocked transactions eventually get and lock the inventory item they need to process.
If there are no common SKUs, all the concurrently running transactions are able to process without blocking.