The demad forecast always get consumed by the sales order. The extra demand a sthe name implies is extra and is not consumed by demand forecast. If you want to say have a constant schedule and would like to have the sales orders/scehdule consuming demad forecast then yo should use backward and foward forecast consumption. E.g. say if the forecast is 100 and sales order is for 110, in the absene of consumption, system will generate production plan for 110, but say if you have foward consumption set up then it will try to get the forecat consumed from that period. Please, note that the MPS may appear to have a weekly or monthy bucket, but system does all the calcualtion at daily level. The calculation can be tricky, and sometimes takes effort to know what system generated a partucular result. But this is the solution that will resolve your issue.