Material issue of partially completed Works order

Material is issued to another worksorder before the worksorder on which it is manufactured is 100% complete (or manufacturing accounting is run for that worksorder) the cost of the item is changed to the actual cost processed through manufacturing accounting divided by the total quantity completed to date.  Best explained in an example.

Example –

1. Create simple Actual Cost (09) Worksorder Item X for Qty 1,000kg and attached Routing (Zero cost) & Partslist with Item Y (1,000kg @ $1/kg)
2. Complete 100kg using Superbackflush – Item cost = $100/kg
3. Complete 50kg using Superbackflush – Item cost = $100/kg
4. Run Manufacturing Accounting without updating the WO status
5. Issues 20kg using Superbackflush