Securing Project related Purchases

Hi,

One of our clients has the following requirement. Request you to provide your valuable suggestions in this regard.

 --In our current site Projects are defined using Oracle Project Suite, say Project A and Project B.

-- Buyer A, who is a key member of Project A is responsible for Procurement against Project A and Buyer B, who is a key member of Project B is responsible for the procurement against Project B.

-- Is it possible to restrict their procurement activities to their respective projects?

-- In other words, Buyer A should be able to create Project related Purchase Orders only against Project A and not Project B wherease Buyer B should be able to create Project related Purchase Orders only against Project B.