Ive been lucky enough to be part of 7 restaurant openings, some as Exec, Head, and Sous, and about to open my eighth this time as Head Chef, luckily they've all been succesess, i learnt a lot from my friend/mentor who would get me involved in all aspects of his business, from how to design a concept, find gaps in the market, how to choose locations, deal with the bank on getting loans, supplier negotiations.. the works, him and his business partners at their peak owned 24 restaurants/bars and most of them different.
A couple of them were twins but in different cities/locations.
The field of dreams idea "if you build it, they will come" is retarded, you need to be so on to it in terms of marketing and advertising its not funny, social media is pretty important these days, especially if you are setting or taking advantage of trends, you either need to stay ahead and adapt or you can have a very short life, my old bosses try and re-vamp every 3 years, then do a re-opening to get back on Everyones radar again.
The people Im currently working for are great, proper hospo professionals, their is an owner/gm who works on the floor as a waiter 5 nights a week (we open 6 days) and the owner/exec who is working the line 5 nights and we do the same hours every week, cleaning down every night too, he probably does a few more as he hits the farmers market every Saturday morning.
Anyway i digress, it really is the whole package that can make or break you.