How to make production order in two steps

hi every one
one of my item is a custom print so
when i make a production order from sales order
first step is to make design and then printing
so do i have to make production order twice one for design and the other for printing or this two both in one production order ?

1st Step FG001 FG001 One Bill of Material, all operation which will show stock at all WIP with operation wise
RM001 Assembly
RM002 Wiring

2nd Step FG001 FG001

Needs to create new Item as FG001-01 with Assembly as Sub assembly					
 FG001-01	which will name as FG with Operation				
	RM001	Assembly			
					Two Bill of Material needs to be created
FG001					Separate Production Order needs to be created as here it will be two production orders
	 FG001-01	FG001 - assembly			Here advantage will be erp will allow to make production of Assemly even if RM002 stock is nt available
	RM002	Wiring