Every software error? True. But essentially every software error, especially errors of significance? Untrue. The Space Shuttle control software was famous for its rigorous process control, and deliberately written in a language difficult to introduce bugs in. Over decades of development and 420,000 total lines of code, it appears that a total of 17 bugs ever made it into software used during a launch, with an average of about 1 bug at a time existing in the codebase. Processes to prevent errors from being introduced played a huge part in this, but the comprehensive verification and simulation process was also necessary to achieve such a low defect rate.
https://www.fastcompany.com/28121/they-write-right-stuff
