I'm trying to understand this set up and am ready to take another stab at it.
So this transaction table is the backbone of the design. It will handle anything from the intake of a part, to the assignment of a part to a machine, to the purchase of a machine or sale of a machine? The transaction type will categorize everything and add/subtract from inventory? Machines will be kept in inventory as well with their details held in tblMachines? But not all transactions will have an fk for Machines? So my parts table may show 2 of this, 5 of that and say 10 machines? If I'm off here, it may be the end of the line for me.