Warehouse as a plant

Dear SAP Gurus,

My client is having Warehouse near Port, where they store the import material and manage the stocks ?

Should we define that warehouse as Plant in the enterprize structure?

Also can we consider the stocks maintained at this warehouse , in the MRP run of our parent plant?

Also while carrying out the mrp run which stock is taken in to consideration, any criteria for the same??

Thanks and regards,

Monica