It depends on the software budget and managers. When I worked a company one the CEO's had an idea about adding a camera to road semaphores so that cars wouldn't stop is the road is empty. I asked: What happens if the sun light hits the camera too much? The guy laughed in my face and told I was being ridiculous. I left the company some months later for other reasons but It was pretty scary to me to hear such words at that time. If you're writing software that might cost someone else's life, the budget shouldn't be a limitation nor time. I'm not aware of any software security regulation, If I'm going to release critical software, Does some entity exists to validates my code? This kind of stuff should exist to block companies that only see the profit of getting a contract.