This makes the program more user-friendly because it is clear that the simulation is now running (and large simulations might need hours until 10% progress is reached which used to be the first progress message).
Example output:
Running Core Simulation...
Time-dependent run with 7296 slices for a time window of 1.0051 microns
Initial analysis of electron beam and radiation field...
Calculation: 0% done
Calculation: 10% done
Calculation: 20% done
[..]
Display also 0% progress of actual simulation.
This makes the program more user-friendly because it is clear that the simulation is now running (and large simulations might need hours until 10% progress is reached which used to be the first progress message).
Example output: