We had a discussion with @ced for the creation of a new module “purchase request”. The “purchase request” functionality is part of the module ‘stock_supply’ and should be extracted to a standalone module.
This module will be the “gathering point” between Stock Supply, Sales Supply and Purchase Requisition towards the Purchase Order and Multi Vendor Request for Quotation.
The tryton issue is the following: Issue 5349: Purchase Request should be decoupled from the stock_supply module - Tryton issue tracker