need clarity on safety stock calculation in MRP Planned %

 Hi,

Any one can help how the system actually derived this below safety stock quantity with given parameters.

bucket days - 6 

Percent - 1000 

Gross requirements 11feb - 6,456 / 12feb --168 / 13feb -- 2976 / 14feb -- 168 / 15feb -- 2688 / 16feb -- 168 / 18feb - 2520 / 19feb -- 168 / 20feb - 1440 / 21feb - 168 / 22feb - 168 / 23feb - 1440

System calculated Safety stock -- 7720 . 

We tried as follows 

Safety Stock = Safety Stock Percent * (Gross Requirements / Safety Stock Days)

= 1000%*(12624(6 days requirement)/ 6 ( bucket days ) = 21040 

But i dont know how system calculated this as 7720 No's . 

Regards

Natchirajan.S