FMEA of Door and conclusions
If Cavemen had done an FMEA of the door when it was invented, this would possibly be the outcome.
| Item | Potential Failure mode | Potential Effects of failure | Severity Rating | Potential Causes | Occurence rating |
| Open door | Person behind door gets door in face | - Broken neck - Death - Bleeding nose |
5-6 | - Two persons trying to pass the same door - Door placed to open into corridor - -”- onto esplanade - Badly placed painting on back of door |
4 |
| Open door | Hidden vicious monster on other side | - Death - Loss of limb - Loss of head |
10 | - Door opens into wilderness - Glass not yet invented, so other side of door can not be inspected |
4 |
| Close door | Limbs get stuck between door and doorway | - Loss of limb - Broken fingers/toes - broken nails - Bloodshed |
7 | - Person is angry and slams door shut - Annoying salesman sticks foot into door - Forgot person behind you |
5 |
| Run through door | Other side opens into chasm Other side opens up on multistory building Other side opens up into ocean |
- Falling off high cliff - Death - Drowning - Bludgeoning - Cuts and bruises |
10 | - Earth activity causes earthquake and resulting chasm on other side of door - Balcony fell down - Global warming caused ocean to rise - Person was in a rush, running through the door, falling off. |
2 |
| … | … | … | … | … | … |
Conclusion
If the cavemen would have been engineers, they would never have invented the door, or at least not used it.