People sometimes ask me how you know if a business idea will work. The answer of course is that you don’t, (business) life is not that easy. Or as I tend to say:
If it was easy, everybody would do it
Which explains exactly why even if such a “can’t fail” plan exists, it would be foolish to follow it. Plans that can’t fail are per definition plans that many people will follow, which means that there is no money to be made with it (supply-demand, that stuff). Which of course in turn means the plan fails, and so it wasn’t a “can’t fail” plan to begin with, merely an easily executable project without reward.