Purchase order

Hi,

I have one purchase order in the status of 400 999, order was placed with 10000 Qty but when checked in F4311 both fields Qty Ordered(UORG) & Qty Received (UREC) is showing same qty 8145.

Then checked in F43121 below is the information.

Qty ordered (UORG) is 10000

Qty Open (UOPN) is 8145

Qty Received (UREC) is 8145

Qty stocked (QTYS) is 8145.

1. User have confirm that he place the order for 10000 and partially receive for 8145 Qty. Then where is remaining qty ie 1855 gone how I could checked this. I have checked in F43121 but no use.

2. If it's partial receipt then how could the order status would be 400 999 and order should be open for remaining Qty to receive ie 1855.