data loading taking so much time

Hi All

we are loading data in SD from DSO to CUBE.Dataloading is happening once in the month but it is taking around 7hrs in datalaod. data load is full. we have 6 years of data is der.kindly help me how to optimize the data laod time. there is start routine in the tranformation of cube for date format conversion.

kindly help me how to reduce dataload time.

Regards