Tell me a way to cancel or exclude OPen PO and open Another PO while running MRP

Navmls

For the demand. I have an open SO for 4 delivery dates for one purchased part. The buyer has already opened a PO with four lines on it buying the part and scheduling the delivery to coincide with the date of need. I would expect the plan to see the open PO and count it as a scheduled receipt. Instead, when I run the plan, it suggests I cancel the four lines on the existing PO, and open a new PO with the same four lines...
The vendor number in the item master is the same vendor number on the open PO. Any way to exclude this cancelling suggestions such as Cancelling of existing PO's and opening new PO's .

Please help

golfer

Probably your existing PO will not meet the demand in time, so it sugegsts to delete it and create a new one with a date to supply the demand. Depending on Reordering Policy you can use Rescheduling period to reschedule the existing PO instead of suggesting to cancel and create new PO

Navmls

For a particular item A, We need to exclude the suggestions(such as Cancel ,Change Qty etc)on all Open PO's if the Supply is equal to demand Qty. IF the supply Qty is less than demand , then system must suggest new . IF the Supply Qty is greater than demand Qty then system must suggest to cancel. this is our requirement. Anyway to set this.
I already done some modifications. but in some cases it is not working. mostly if supply Qty is greater than demand ,then the canceling is not working .How to set this .please help. urgent.