Your comparison of the commissioning of large industrial plant to the flight testing of multi billion dollar aircraft systems doesn't make any sense... whatsoever!
I won't take the thread off on a tangent, but the various replies have done much to enlighten me, particularly Two_Squirrels. Many large industrial plants are hideously complicated, incorporate many untested systems, and are fabulously expensive. When they go wrong they tend to do it in rather unpleasant and often massively fatal ways, so not a worthless comparison.
My post was to question the apparent concept that the aircraft would be built and then some brave chaps would take it up for a spin to see how, or if, it worked. My question has been answered.
Let's leave it at that.