Automatic buyer assignment on Purchase Orders

Question

Is it possible to change the buyer assignment hierarchy?
We currently assign a buyer to most categories. Requisitions are then assigned a buyer dependant on category selection.
If a requisition is linked to a CPA or BPA, the PO is automatically created and approved. The buyer named on the resulting PO or release is depends if a buyer has been assigned to that category.
Example 1
The “Stationery” category is assigned to Buyer A
Buyer B is the named buyer on the CPA
The resulting PO is created with Buyer A as the named buyer.
Example 2
The “Furniture” is not assigned to a buyer
Buyer B is named on the CPA
The resulting PO is created with Buyer B as the named buyer.
The current configuration is cause issues where requisitions for mixed goods are being split into several orders.
The outcome we need is to change the assignment of the buyer on the resulting PO. We would like to ensure that the Buyer named on the CPA is always the buyer on the resulting PO.
Example 3
The “Stationery” category is assigned to Buyer A
Buyer B is the named buyer on the CPA
The resulting PO is created with Buyer B as the named buyer.
Is it possible force Purchasing to always place the CPA buyer on the resulting PO.

Answer 1

You have to customize "PO Create Documents" purchasing workflow.
Please see:
Purchaing user guide > Procurement Workflows > Workflow for Creating Purchase Orders and Releases > "Summary of the Get Buyer Subprocess" section.
It will be easy, just exclude few functions in this workflow and try to leave only "Get Buyer From Source Doc".