The issue will be explained by the following example, where all the provided values are for example purpouses only:
You are performing a Physical Inventory Count on 01.09.2018 (set as a Key Date) and you are entering the results on 09.09.2018. In the meantime (the period between 01.09 and 09.09) there are changes in stock and the system is considering those changes in the PI Count document.
You are expecting that you should be able to enter the Actual Quantity for the Key Date and not for the date when the document is created.
SAP Business ByDesign
Reproducing the Issue
1. Physical Inventory Count created with key date 01.09.2018.
Example material: ABC (ABC represents the Product ID) - 10EA on stock.
2. count task executed by employee 01.09.2018.
Example material: ABC - 8EA counted.
3. some customer ordered 5EA of material ABC; the order was processed and material shipped before 09.09.2016.
Example material: ABC - 5EA on stock.
4. count task finished 09.09.2018.
Example material: ABC - 8EA reported and finished.
There are still 5EA on stock.
5. Physical Inventory Count approved 09.09.2018.
Example material: ABC - 8EA on stock.
Result: Stock has changed from 5 to 8 which is +3 instead of -2 (actually 8 have been counted and 10 had been on stock).
The Physical Inventory Count is an inventory adjustment which works only on the current inventory snapshot.
When you do an inventory adjustment, it will always adjust the current inventory.
When you do an inventory adjustment with a key date which is not current date, the system performs the adjustment to the current inventory snapshot but posts it at a different date.
Even though you have done the inventory adjustment with a different key date, it will adjust the current inventory only.
This is an expected system behaviour.
KBA , AP-PIP , Physical Inventory Processing , AP-PIP-PIC , Physical Inventory Count , Problem