HAS ANYONE IMPLEMENTED A USER EXIT IN SALES WHICH WILL DETERMINE WHICH PLANT TO SHIP FROM BASED ON AVAILABILITY OF MATERIAL?
Hope I understood your question correctly...
When you create a sales order, you can view available quantity in each warehouse by right clicking the WH field and select the option Warehouse Balance Report.
Another screen will open up to show the quantity level for this item in each WH. at this point you can double click a certain WH to pull from.