Hi Miche,
Thank you for your reply and further clarification.
Perhaps this the outcome you are looking after in your summary table?
I noticed that in your Data enter sheet, some data entries are not listed, such as Stock Pack 18 -94998, Stock Pack 13-95071, which there are some difference from your example of output. Hence the formula I used only calculate the data you provided in “Shopfloor-using” table and “Office-Receiving/Ordering”

Based on my understanding, you are trying to track the stocks left in Summary table, which is sum up all the data in “OFFICE - RECEIVING/ORDERING” table and minus the sum of “Qty used” in “SHOPFLOOR – USING” table”
In this scenario, I am using SUMPRODUCT formula first to sum all records for “Bars/Tubes Qty on Order”, “Bars/Tubes Received” and “Quantity Produced” in “OFFICE - RECEIVING/ORDERING” table based on the category of “Stock Pack” and “Bar/Tube”, which it will get all the stocks you ordered, received and Produced.
Then using SUMIFS formula to sum all the data for “Qty used” in “SHOPFLOOR – USING” table to figure out the total used product based on the category of “Stock Pack” and “Bar/Tube”
After that just minus the results from two formulas, which it get the stock summary in the summary table.
Here is a file I edited based on your shared file. Hope it can give you a clear picture with the formula I used.
Note: I added some new data in Data entry sheet for testing the formula.
MICHE STOCK edited.xlsx
Best regards,
Dihao