Although it is a bit overly dramatic (which might explain why it's a hit) I've always enjoyed the Bar Rescue series where Jon Taffer tries to fix broken bar businesses. The early episodes got more into the math of what works but Taffer screaming at owners was more popular so you see much less of that in later seasons.

https://en.wikipedia.org/wiki/Bar_Rescue

I know a guy that goes in and rescues bars in exchange for a percentage of the increase in value as they're later sold. He swears that the core of what Taffer does is exactly how he operates.