Is overall pressure ratio same as compressor pressure ratio for a gas turbine engine? For a typical gas turbine engine, turbofan in particular, is the compressor pressure ratio same as the overall pressure ratio? 
For modelling purposes can we use the same value of overall pressure ratio for compressor pressure ratio too? 
If we do so, will we get accurate results for performance?
Modern turbofan engines typically have several stages of compression, the overall pressure ratio is the ratio of the highest pressure to the intake pressure. But the pressure ratios of each compressor can be a different.

The fan and booster add a bit of compression, followed by an optional intermediate pressure compressor and finally the high pressure compressor.

Because of these multiple shafts and therefor having some parts of the compressors not working on their design point you probably won't get accurate results by simulating a single stage compressor.