Forget about the simulation. You said, "I'm going to check it practically." That is what I am talking about.
Say the simulation predicts it breaks at 120 inches and doesn't break at 110 inches.
For your practical test, you physically drop a real part at 100 inches and it breaks. What do you do next?
Let's say you practically drop the next sample at 80 inches and it also breaks.
Let's say you practically drop the next sample at 60 inches and 40 inches and they also break.
Finally you get down to 20 inches and you get a glass that doesn't break.
Do you say that the glass breaks between 20 and 40 inches?
No, because you drop another sample at 40 inches and it doesn't break then you drop another sample at 20 inches and it does break.
What do you say is the height at which the glass will break in a practical test?
The point is that there is a range of heights with varying probabilities of breakage.
The plot I showed is one way to quantify the probability of breakage as a function of drop height in a practical test.