Order Settlement Concept

Dear all

Please see below situation and reply me on what logic system calculated MAP.

Price control indicator is V for FERT

Order Created and Confirm and GR n GI done.

before that FG MAP WAS 8,121.91

Stock -115 MT

after making GRN OF 100 MT

new stock is 215 MT

and after settlement FG New MAP is 6,630.51

before settlement Order has shown Variance between Planned and actual is 446257.47-

As we are using Price control As V so on settlement system changes our MAP.

Plz tell me how system calculated This new MAP