When MRP runs ,it creates Planed Purchase and planned Production orders.
Scenerio1: if I firm Planned Production order first with standard marking option it is marked(reserved) against its demand source( Forecast, Sales Orders, Safety stock).later if I firm Planned Purchase order created as supply to this production order with NO Marking, new PO's created after firming are not reserved aging this specific production order and can be a supply to any other demand too.
Scenrio2: in the Same example if I create Purchas order first with NO Marking ,and then firm planned Production order with Standard Marking ,components (Production BOM) get market(reserved Order) to PO .
my requirement is in either case PO should be left unmarked to production BOM lines , i can understand system behavior in second scenario but is there any setup that keeps marking to the Source (Sales,Forecast,TO,Safertstock) but keep Supply unmarked.