JBA ML - Uncoupling Accounts Payalbe from the supply process

Has anyone had to uncouple Accounts Payable from the
purchasing/receiving/inventory process?

We are running just about everything except sales and order fulfillment out
of System21.  Our corporate parent is consolidating all financials (general
ledger, accounts payable, payroll).  In the accounts payable change,
corporate wants us to send purchase orders and receipts to them.  The
supplier will send the invoices to the corporate office where they will be
matched.  We will then receive the matched receipts back to update the
purchasing records.  The problem appears to be with sending the purchase
orders for direct materials.

We are using standard cost on most direct materials, but a few are FIFO
costed.  Direct material items are loaded in the item master with the
purchases accounts = the stock accruals account.  When the 3-way match
occurs, the stock accruals accounts is debited and the matched account
credited.  If there is a variance, then the appropriate variance account is
debited or credited.  When the check is cut, the matched account is debited
and the cash account credited. AFI run on inventory is then the vehicle to
hit the correct cost center for the item.  I believe this is the standard
in System 21, and it allows us to account fo the same direct materials
being used in multiple manufacturing cost center.

The corporate requirement is for the purchase order to specify the account
associated with the cost center (the same one that we build all kinds of
nifty rules to determine where AFI will put it), the theory being that the
purchaser knows where the material will be used.