Forecast consumption difference in ECC and APO

Hi,

In my system, the forecast consumption in ECC and APO are not equal. I am using the standard requirement strategy of 20 and both backward and forward consumption. In ECC, 1st week of May forecast consumption is much lesser than that in APO for a particular product. In 2nd week of May also the forecast consumption in ECC is lesser than that in APO but the difference is less. But the forecast consumption in 3rd week and 4th week of May are equal. So can anybody let me know why the forecast consumption is not equal.

The forecast is getting released to both APO and ECC on adhoc basis and for this particular product it was last released on 08 May from the May month onwards.

Thanks & regards