How to set up a scheduled purchase orders from a Global Agreement?

Is it possible to set up a schedule where standard purchase orders are automatically created from a Global Blanket Agreement?  I know this is possible with releases and Local Blanket Agreements, but we do not use Local agreements.

For example we have a Global agreement with prices for monthly maintenance.  The process is then to create a requisition each month from the supplier item in the iProcurement catalog, then it is manually created into a standard PO by a buyer. What we would like is when the Global Agreement is created and approved, a standard PO is generated each month for the required quantitiy without any manual internvention or requisition being raised.