Doesn`t make sense ???

[Klem]

Data by definition is known facts. The output of simulations is a not facts.

Data is information which researchers use as fuel to analyse, hopefully resulting in phronetic wisdom.

I don't think anyone is saying the output of a simulation is factual, or I think you mean matches [exactly] reality. Just because it does not match reality to your definition of precision does not mean it is useless. There are variables that QL does not take into account, plus the inherent range of pressures and velocities with subsequent firings of the same load.

I find it a useful aid and has served me well. It has saved a lot of money and I will continue to use it.