My 1st request: planning safety stock

Hi !

I work at Revlon Italy - Rome, Italian distributor for Revlon Int.,
cosmetics.
We only buy and sell products (execpt some items) for italian market.

I'm planning /purchasing manager and I have also previous experience as a
BPCS consultant.

We have a BPCS V6.0.04.
We have monthly customer forecasts & monthly planned orders to suppliers.
I'm trying to set-up MRP140 as to have a safety stock at the end of the
previous month to cover the following month's fcst.

Example (goal): item ABC
STOCK 30/06/08 1000 pcs
FCST Pl.Ords. Due date Bal.end month
1/07/08->31/07/08 1200 pcs 900 pcs 1/07/08 700 pcs
1/08/08->31/08/08 700 pcs 800 pcs 1/08/08 800
pcs
1/09/08->30/09/08 800 pcs ........ .......
........

I tried to use Order Policy: G, with Period Order Days: 28,
but the result was to have planned orders in the same month of Fcst, not
the month before.
Safety stock: 0 pcs

Example (results): item ABC
STOCK 30/06/08 1000 pcs
FCST Pl.Ords. Due date Balance
1/07/08->31/07/08 1200 pcs 200 pcs 1/07/08 0 pcs
1/08/08->31/08/08 700 pcs 700 pcs 1/08/08 0
pcs
1/09/08->30/09/08 800 pcs ........ .......
........

Is there a way to anticipate due date as to reach my goal?

Thanks & regards

Ugo Capozzi
www.revlonitaly.com