Generally if it's possible that a complete failure of process happens, designers will plan for that. Anything outside of fully automated assembly processes with

Generally if it's possible that a complete failure of process happens, designers will plan for that. Anything outside of fully automated assembly processes with interlocks and safety checks warrant that to a decent designer. You cite cost of redesign but we're talking design in the first place. What's on the table in this discussion is design, not response to failures.