Standard reservation entries in Business Central do not automatically calculate whether you can actually fulfil a customer’s demand on the date they want it. You have to check inventory profiles manually and reopen existing reservations to make room for new ones.
The Assigned Quantity feature solves this. It calculates whether a sales order line is possible to deliver based on the lowest available inventory point before the requested date, and assigns the quantity to the line without locking it in a hard reservation.
If you reserve a sales order line with standard functionality, Business Central tells you the total available quantity is already reserved. You then have to reopen and re-reserve existing reservations manually, which becomes heavy and complex when you have many sales order lines.
The limitation of standard reservation entries in Business Central
One of the problems with standard reservation entries is that they do not calculate the best fit for your customer automatically. You are left to work out whether you can meet a delivery date on your own.
Take a concrete example. You enter a sales order line for item number 1000. The customer wants the item delivered on January 29, and they want 13 pieces.
Reading the graphical inventory profile
If you look at the graphical inventory profile for this item without an assigned quantity, you are just looking at the profile as it stands. In this scenario, on January 25 you have 16 pieces in inventory. That is the lowest inventory point in the relevant period, so it should be possible to provide the 13 pieces the customer wants.
How Assigned Quantity calculates whether delivery is possible
When you enter 13 on the line, the Assigned Quantity calculates that this is actually possible and assigns 13 to the line. If you then look at the inventory profile again, your inventory still looks healthy, dropping to 3 at the lowest point but never going negative.
The key here is the mathematical calculation. Assigned Quantity works out whether it is possible to fulfil your customer’s demand, and it does so without forcing you into a hard reservation that blocks other lines.
Why standard reservation becomes a problem with many sales order lines
The difference shows up clearly if you try to reserve the same line with standard functionality. When you go into the reservation functionality, you can see that your total available quantity is already reserved. If you try to auto-reserve, Business Central tells you it is not possible.
To get around this, you have to change or reopen an already existing reservation and re-reserve. That can be quite complex and quite a heavy workload, especially when you have many sales order lines to handle. Assigned Quantity avoids this by doing the calculation up front instead of locking quantities through traditional reservations.
Q&A
Why does standard reservation in Business Central not automatically fit a customer’s demand?
Standard reservation entries do not calculate the best fit for your customer. They do not check whether the requested quantity can be delivered on the requested date, so you have to verify inventory profiles and adjust reservations manually.
What does Assigned Quantity do differently from standard reservation?
Assigned Quantity calculates whether it is mathematically possible to fulfil a customer’s demand based on the lowest available inventory before the requested delivery date, then assigns the quantity to the line. It does this without a hard reservation, so it does not block other sales order lines.
What happens when you try to auto-reserve a line that is already fully reserved?
Business Central tells you the reservation is not possible because the total available quantity is already reserved. You then have to reopen an existing reservation and re-reserve to make room for the new line.
Why is standard reservation a problem when you have many sales order lines?
Reopening and re-reserving existing reservations manually is complex and creates a heavy workload. The more sales order lines you have, the more time-consuming this becomes, which is why Assigned Quantity’s automatic calculation is more practical at scale.