Simulation and regression testing
Exercise the flight software against the real airframe, before every release.
Simulation and regression testing
Flight software changes are usually validated by flying them, which is slow, weather-bound and risky, and covers only the handful of conditions you can arrange. Most releases reach the air having been tested against a fraction of what they will meet.
A simulator is only worth trusting if it models the actual aircraft, and most bolt-on simulators use a generic model that does not match the airframe that flies. A pass in a simulation that does not represent reality is a false comfort.
Crosswind simulates against the airframe definition from Planform, so the model is the aircraft. Autonomy from Waypoint and failure logic from Failsafe run as an automated regression suite, so every release meets its edge cases on the ground first.
Because Crosswind uses the same airframe model the programme designed, a change that passes simulation is a change tested against the real aircraft, not a stand-in.
Tell us what you are flying and where the programme is losing time. We will tell you honestly which of these helps and which does not.