Unit of measure issues

Base unit of measure ITEM 1=PCS=Has production BOM
–I have setup like
with rounding 0.0001
1 PCS of production BOM is 3 KG.
–Because after production of ITEM 1 goes in PCS. and related KGs are not updating in that inventory.
–I have to consume that in grams in different BOM
–how to setup it?
thanks sir

Create another UOM for “Grams” with the “Qty Per” of 3000. Use that for your new BOM.

Where are you expecting to see the related KGs updated? Inventory is stored only in base UOM. Only advanced warehousing stores inventory levels in specific UOM. But even that is only recorded in the transactions UOM.