Manufacturing - booking back the remaining part of a single unit

If you book out a 50Kg drum (held as a unit of 1) and use 5Kg from the drum, how do you book the remaining balance back into available stock?

This is the old problem of the chain for the bicycle bought in as a 20kg drum and part consumed in a batch by 10 lengths of 0.7 m.

How do you report the consumption (no such report) and how do you book the single drum back into stock with part of it missing?

It is not acceptable to the owners to show the inventory as consumed if only a part has been.




I believe the Process add-ons handle this using catchweights, 1 drum is 50kg, use 5kg and it is 0.9 left. You can do this by decimals, but it does not handle the fact you move a drum each time, so you need to have one in the BOM and consume 0.1.