It is not a rare situation that company which is implementing a new information system, in this case PoIS, already have modules of another information system or some specific software used in its business which have to be integrated with PoIS.
The PoIS has been integrated with other software successfully many times before, because PoIS is meant to work on different platforms, various DBMS systems (databases), communicate with web services, etc. which all means that PoIS is opened for communication with the external environment.