1. Create an Assembly Item > Set Effective BOM Control = Effective Date
2. Go to Transactions > Manufacturing > Enter Work Orders.
--- Add Item.
--- Set Status = Planned
--- Hit Save.
3. Edit Assembly Item > Change Effective BOM Control to ‘Revision Control’ > Hit Save.
4. Edit Work Order.
Notice that the ‘Revision’ field is greyed out.
Had the Status of the Work Order been ‘Released’ (instead of 'Planned') before Effective BOM Control was changed, ‘Revision’ field would be editable in the Work Order.
This is logged under Enhancement 388967: Change Assembly to use Revision Control > Edit Work Order > Unable to set Revision.