Delete request from PSA

Hi,

I have a requirement where I have to delete the previous request from PSA before I load the data next time to BW.

The ETL frequecny is 8 hrs. This means for every 8 hrs I will load the data to BW using Process chain and for each cycle of loading I have to delete previous PSA request.

I checked the option of using "Delete PSA Request" in process chain but there is no option for deleting the requests in hrs.

Can anybody help me.

Thanks in advance.

Amit