Looking for input about the Safety Stock

I'm looking for input from Community subscribers about the Safety Stock which is used for replenishment purposes:

1) Are you using the 'Calculate Replenish Parameters' process (IN_RPL_PRM) to calculate the Safety Stock?
2) If no, why?
3) If yes, is the calculation meeting your expectations?
4) Are you aware of any specific scenario when the process is not calculating the Safety Stock in the right way?

Thanks in advance for your input.

Frederic