This indicator controls whether the system checks to see if the number of allowed partial deliveries was exceeded during the subsequent delivery split.
The current number is taken from the corresponding sales order for this check. The system will only allow you to create the last allowed delivery by using a delivery split if the sales order item is listed in the system as being delivered completely. In other words, no open quantites can exist for this order item before the split. If open quantities existed, you would need to use the last allowed delivery to deliver the open quantity rather than to split an existing delivery.
If you set the amount of partial deliveries to 0, the system assumes there is no limit and allows you to create as many partial deliveries for an order item as you like.