SpaceX approach when it comes to safety is to make sure everything that can go wrong goes wrong during testing and lesser value launches, so that when it is time to put people onboard, the issues will have been fixed.
NASA is about making doing right the first time though careful design.
For SpaceX approach to work, they need to test a lot, with a lot of explosions, so they need to make a lot of rockets, they also need repeatability. That's why they are using assembly lines and mass production techniques.
Which approach is the best, I don't know. The traditionally designed Delta IV never failed, but on the other hand, we lost two Space Shuttles and their crews. As for the Falcon 9, it had a couple of failed missions, but it has proven very reliable over time.
NASA is about making doing right the first time though careful design.
For SpaceX approach to work, they need to test a lot, with a lot of explosions, so they need to make a lot of rockets, they also need repeatability. That's why they are using assembly lines and mass production techniques.
Which approach is the best, I don't know. The traditionally designed Delta IV never failed, but on the other hand, we lost two Space Shuttles and their crews. As for the Falcon 9, it had a couple of failed missions, but it has proven very reliable over time.