This is the best answer in my opinion as the vehicle safety standards for programmable safety systems are derived from IEC61508 which, among other things, gives

This is the best answer in my opinion as the vehicle safety standards for programmable safety systems are derived from IEC61508 which, among other things, gives guidelines for methodologies intended to create and validate software with target known failure rates. See this for a brief overview https://www.google.com.au/url?sa=t&source=web&rct=j&url=https://www.researchgate.net/profile/Munir_Afridi/publication/268378225_C_PROGRAMMING_IN_SAFETY_RELATED_ENVIRONMENT/links/5469c5980cf2397f782d9977/C-PROGRAMMING-IN-SAFETY-RELATED-ENVIRONMENT.pdf&ved=2ahUKEwiw0vPv1p7bAhXJabwKHWQBBJk4MhAWMAJ6BAgJEAE&usg=AOvVaw0xIgVn2toXHrMKXz0mdW2N https://www.google.com.au/url?sa=t&source=web&rct=j&url=http... Functional safety is a specialised branch of engineering all of its own.