Creation of PR from SO

Dear All,

Our customer is working in EPC business, where they are handling both internal (within group) and external projects. As our business is handling projects, ours is PS driven system, where Project system (PS) is a primary system. All project related activities are tracked from PS system. Currently whenever the contract get awared to business, the process in SAP start from procurement (i.e. creation of PR from PS system). But now the requirement is to start the process in SAP from Sales contract, with PS as a primary system.

We are seeking help to understand the to be process, which will start from Sales order through PS system. Here there are two types of procurement;

1. For the customer (i.e part of procurement contract), here business will not do GRN for the material (similar to thrid party procurement).

2. For the construction purpose, where business will physically receive the material through GRN.

Request you all, please help us to map the process.

Regards,