|Two things have to happen in order for you to get "Delta Volume" values:|
1 - The old values have to be retained and stored someplace.
2 - There has to be a formula to calculate the difference between the old values and the new. That formula could be in a cell, in a macro or in your head.
You said: "I don't know if there is an increase or decrease in the volumes to be produced (this is important because it is linked with the information for the purchasing dept.)"
How is it linked with other information? It seems to me that this relates to Item 2 mentioned above.
If you don't currently have these Delta values being calculated in the sheet, how are you passing this information along to Purchasing?
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