Friends come and go but enemies accumulate.
Some suggestions for you :
If you improve or tinker with something long enough, eventually it will break or malfunction.
The Ninety-Ninety Rule of Project Schedules - the first ninety percent of the task takes ninety percent of the time, and the last ten percent takes the other ninety percent.
A failure will not appear until a unit has passed final inspection.
The compromise will always be more expensive than either of the suggestions it is compromising.
If your project doesn't work, look for the part that you didn't think was important.