Need to invoice client partly

Hi

We have E-buss suite (Financials + Inventory & Order Management) .

Invoicing clients are done via Order Management module and  invoice is generated in Receivables automatically.

We have now a requirement where we need to bill a client in installments .

E.g. 50% on confirmation of order,40%on delivery and 10%on completion of the work.

Is there a way to do that in Order Management, we also need to take into account the Inventory module for stock items..

Any feedback will be appreciated.

Rgds

Prem