The intended usage scheme of SIMEX platform is that of a python module in either an interactive (i)python session or a python script. Hence, the first thing to do is to import the SimEx API module.
>>> import SimEX
A good starting point for finding examples on how to use SIMEX platform modules are the tests under
Tests/python/unittest/SimExTest/. Each Calculator is tested, and the test-suite
PhotonExperimentSimulation/PhotonExperimentSimulationTest.py contains some SIMEX platform workflow examples for complete start-to-end simulations.