Sorry if I made you confused!
we have a special vendor that procure specials kinds of materials for our production. According to our supplier sometimes these material numbers are changed or replaced according to our production, time, stock availability,....
Because of the rate of changes and difficulty of tracking these changes in purchasing documents, purchasing department prefer not to create real PR. instead of that just email their requirement to supplier. For example purchasing department announce their rough requirement. they just mention the name of packs (packs of material). after finalization of the order, packing list is delivered.
You know PR document is just an information document for our purchasing organization to start procurement process.
As I mentioned, this happens just for one of our procurement processes!
thank you for your attention
Best Regards