Open ordered quantity

 Hi,

     I need to get open ordered quantity, for this Iam using the requested_quantity-shipped_qunatity. Do we need to consider the RMA lines into consideration? If so, how we need take that calculation. I saw some data even for RMA lines when the line got got returned, the shipped_quantity is being populated. But I saw this isn't for all RMA lines. So when the shipped_quantity for RMA lines will be populated?

        My assumption is as the open orders quantity I required, open orders are those which need to be shipped, so we may't require to consider the RMA lines. If anyone suggest me in this regard will be helpfull.