Hi,
Sure we are rather discussing how to tailor and map the PM methodologies with ASAP in effective and beneficiary way. I fully agree with Jan - that PMI and ASAP are two layers of right SAP project management, communication and execution. Where PMI is "native" for ASAP also PRINCE2 may be very effective project communication and organization layer for SAP project as I am experiencing that right now. Please look in my blog:
http://scn.sap.com/community/asap-methodology/blog/2014/03/26/prince2-for-sap-erp-implementations
Cheers
Waldek