The Production Cell, marked as "Default" in the Production Cells List (see Basic Data), will be displayed in the “Default Production Cell” field for each new Product Structure. It can be optionally changed here (if necessary). After this, the Default Production Cell will be passed from Product Structure to the new Production Order where it also can be changed. So, why the correct Production Cell is so important for the Production Order? It is important, because allows defining the proper Production Cell (together with related Inventory Addresses) where the Components (Inventory Parts) can be RESERVED and ISSUED for the Production Order if such Components have Issue Part Method = "From Production".