Jason Cohen (founder of WP Engine, among others) recently wrote a super interesting blog post "Excuse me, is there a problem" [1].
In his post, he explains why even identifying an actual problem and solving that problem isn't usually enough to create a viable business.
Further down in the post, he also comes up with a scoring system to rate business ideas (with all obvious caveats and exceptions of such a calculation).
One cool aspect of this is that you can simulate how your positioning (e.g. higher pricing, combined with narrower target audience) may change your chances of survival as a business.
Being a Google Sheets noob, I created an interactive version of the calculator and linked it above. Hope you find it interesting :)