Hi, I'm new to Odoo and on v9. I just want to share this solution which I am not sure is this a proper method but at least work for me.

Currently, we purchased item A, B, and C. Vendor shipped to us in bulk back separately. We sell product D which is the assembly of A + B + C. Warehouse folks walk by and if they see (visual) D is low or empty, then they unpack the A, B, and C and assemble a few of D. But this is not efficient. This overall operation is manually decided and operated.

With Odoo, I use the BOM, work order, safety stock, purchase requisition to automate this process.

Product D is a BOM contains item A, B, and C. Product D has a safety stock. If D stock is under the safety stock, it creates work order for item D with item A, B, and C. With the work order, warehouse perform the assembly of A, B, and C into D. Item A, B, and C also have a safety stock which will trigger the purchase requisition.

There may be extension or module which may help on this. But as a newbie, I just use what I know and comes in standard.