I remember hearing from the chief program officer for the software of the new joint fighter the F-35, in the US, five or so years ago. He said "I'm the chief software program officer, and I'm absolutely certain that the approved requirements for the software for this plane cannot be met, and there's nothing I can do about it because there are so many forces being brought to bear on these requirements." (45:45 - 46:18)
[1] https://www.heidelberg-laureate-forum.org/video/lecture-hint... (27 August 2015)