Reimplimentation from PP to PPPI

Hi Experts,

We are re-implementing in one of the client who is in processing of die-chemicals .From past 20 years he is in discrete manufacturing and now he wants to go for Process industries solution without PI sheets(PP PI). I understand that basic masters of PP (like work center and Recipe)  and configuration like order type will change.But I wanted to understand list of activities to be done to move from SAP PP to SAP PP-PI. Including major configurations, master data, cut over (to move stock and order data) steps required from other integrated modules.

One more point to be noted that the production system is going to be the same.In the existing system we are suppose to change it from PP to PPPI.

Request your help with coming up with important points which can be very useful in my consideration

Thanks and Regards

David.