Hi priya ,
To answer your query SPIOC and process map may be the same visually but are not actually the same . The main diffrence that you would have to do after you make a SIPOC is ensure process owners and stakeholders . In a High level process mapping the focus is always on process overview and not who is driving it or which department owns the complete process. A good well defined SIPOC will ensure that outliers like dependcy of process on deapatments would be indetified along with correct person who would drive change in those departments . Hope this clarifys your query .